{"id":204,"date":"2015-01-20T08:35:13","date_gmt":"2015-01-20T08:35:13","guid":{"rendered":"http:\/\/biomedpharmajournal.org\/?p=204"},"modified":"2020-04-23T11:10:01","modified_gmt":"2020-04-23T11:10:01","slug":"synthesis-of-heterocyclic-stable-phosphorus-ylides-from-reaction-between-triphenylphosphine-and-activated-acetylenic-esters-in-the-presence-of-biological-active-nh-heterocyclic-compounds","status":"publish","type":"post","link":"https:\/\/biomedpharmajournal.org\/staging\/vol1no1\/synthesis-of-heterocyclic-stable-phosphorus-ylides-from-reaction-between-triphenylphosphine-and-activated-acetylenic-esters-in-the-presence-of-biological-active-nh-heterocyclic-compounds\/","title":{"rendered":"Synthesis of Heterocyclic Stable Phosphorus Ylides from Reaction Between Triphenylphosphine and Activated Acetylenic Esters in the Presence of Biological Active NH Heterocyclic Compounds"},"content":{"rendered":"

Introduction<\/strong><\/p>\n

Phosphorus-carbon bond formation[1-15]<\/sup> is an active and important research area, as new reactions are continuously being developed for the preparation of organophosphorus compounds such as phosphinates and phosphonates.[16-24]<\/sup> Over the last few years, the quest for the synthetic efficiency has gained remarkable importance, partly due to the need reduce waste.25<\/sup> Given the increasing industrial, biological and synthetic impact of organophosphorus compounds.[26-30]<\/sup> The successful attack by nucleophilic trivalent phosphorus on a carbon atom is facilitated when the latter is part of, or conjugated with, a carbonyl group, or when it is part of an unsaturated bond otherwise activated.[27-29]<\/sup> There are many studies on the reaction between trivalent phosphorus nucleophiles and \u03b1, \u03b2\u2013unsaturated carbonyl compounds in the presence of a proton source such as alcohol or phenol.[31,32] <\/sup>Here we wish to report a simple one-pot synthesis of heterocyclic compounds-containing stable phosphorus ylides. Previously, the pyrazole and thiazole moieties and their derivatives have been used commercially as pharmaceuticals, pesticides and dyestuffs.[33]<\/sup> Thus, the reaction of triphenylphosphine 1 with dialkyl acetylenedicarboxylates 2 in the presence of NH heterocyclic compounds 3 such as 3-methylpyrazole and etc were undertaken to generate the corresponding stable heterocyclic phosphorus ylides 4 in excellent yields (see Scheme 1).<\/p>\n\n\n\n
\"Scheme<\/td>\nScheme 1<\/strong><\/p>\n

 <\/p>\n

Click here to View\u00a0scheme<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Result and discussion <\/strong><\/p>\n

In the current work, stable phosphorus ylides from reaction between triphenylphosphine 1<\/strong> and dialkyl acetylenedicarboxylates 2 in the presence of N-H acids 3, such as (2H)-3-pyridazinone, 1-phenyl-3-pyrazolidinone, 2,4-thiazolinedi- one, Rhodanine,\u00a0 4,5,6,7-tetrahydroindazole and 3-methylpyrazole\u00a0 led to 4 in excellent yields (see Scheme 1). The reactions (4a-m) were carried out in ethyl acetate solvent at room temperature and were finished within a few minutes. The 1<\/sup>H and 13<\/sup>C NMR spectrum of the crude product clearly indicated the formation of compounds 4a-m. Any products other than 4a-m could not be detected by NMR spectroscopy. The structures of compounds 4a-m were deduced from their IR, 1<\/sup>H, 13<\/sup>C, 31<\/sup>P NMR spectra, Mass spectrometry and elemental analysis. The mass spectra of compounds 4a-m displayed molecular ion peaks at appropriate values, which were consistent with 1:1:1 adducts of NH heterocyclic compounds, dialkyl acetylenedicarboxylates and triphenylphosphine. Although the presence of the 31<\/sup>P nucleus complicates both the 1<\/sup>H and 13<\/sup>C NMR spectra of 4a, it helps in assignment of the signals by long-range couplings with the 1<\/sup>H and 13<\/sup>C nuclei (see Experimental section). The 1<\/sup>H, 13<\/sup>C, and 31<\/sup>P NMR spectra of ylides 4a-m are consistent with the presence of two isomers. The ylides moieties of these compounds are strongly conjugated with the adjacent carbonyl group and rotation around the partial double bond in (E<\/em>)-4 and (Z<\/em>)-4 geometrical isomers is slow on the NMR timescale at ambient temperature (see Scheme 2). As can be seen, only one geometrical isomer was observed for di-tert-butyl derivatives of 4, presumeably, because of the bulky tert-butyl groups. (see Scheme 2).<\/p>\n\n\n\n
\"Scheme<\/td>\nScheme 2<\/strong><\/p>\n

 <\/p>\n

Click here to View scheme<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

On the basis of the well established chemistry of trivalent phosphorus nucleophiles, [3-7] <\/sup>it is reasonable to assume that phosphorus ylide 4 results from the initial addition of triphenylphosphine to the acetylenic esters and subsequent protonation of the 1:1 adduct by the NH heterocyclic compounds to form phosphoranes 4 (see Scheme 3).<\/p>\n\n\n\n
\"Scheme<\/td>\nScheme 3<\/strong><\/p>\n

 <\/p>\n

Click here to View scheme<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

The 1<\/sup>H NMR 500 MHz spectra of 4a showed four sharp lines at \u03b4<\/em> = 3.14, 3.72, 3.61 and 3.66 ppm arising from methoxy protons. Methine protons appeared as two doublet peaks at \u03b4<\/em>= 5.64 ppm (1H, d, 3<\/sup>J<\/em>PH<\/sub>=17.0 Hz, P-C-CH<\/em>) and 5.75 ppm (1H, d, 3<\/sup>J<\/em>PH<\/sub>=18.9 Hz, P-C-CH<\/em>) respectively for the E and Z geometrical isomers. The aromatic protons appeared as a multiplet at \u03b4<\/em> = 6.65\u20137.90 ppm (18H, m, 3C6<\/sub>H5<\/sub> and C4<\/sub>H4<\/sub>N2<\/sub>O). The 13<\/sup>C NMR spectrum of 4a displayed 28 distinct resonances in a good agreement with the mixture of two conformational isomers. The 1<\/sup>H and 13<\/sup>C NMR spectra of compounds 4b-m are similar to those of 4a, except for signals from the ester group which appear as characteristic resonance lines with the corresponding chemical shifts. The structural assignments of 4a-m were made on the basis of the 1<\/sup>H and 13<\/sup>C NMR spectra that were supported by their IR spectra. The carbonyl region of the spectra exhibited two distinct absorption bands for each compound related to ester groups of yilde moiety (see Experimental section).<\/p>\n

Briefly, we have prepared novel phosphorus ylides using a one-pot reaction between triphenylphosphine and dialkyl acetylenedicarboxylates in the presence of strong NH heterocyclic compounds. The present method carries the advantage that, not only is the reaction performed under neutral conditions, but also the substances can be mixed without any activation or modifications. Heterocyclic compounds-containing stable phosphorus ylides 4a-m<\/strong> may be considered as potentially useful synthetic intermediates. It seems that, the procedure described here may be employed as an acceptable method for the preparation of phosphoranes with variable functionalities.<\/p>\n

Experimental\u00a0 <\/strong><\/p>\n

Melting points and IR spectra of all compounds\u00a0 were measured on an Electrothermal 9100 apparatus and a Shimadzu IR-460 spectrometer respectively.\u00a0 <\/sup>Also, the 1<\/sup>H, 13<\/sup>C, and 31<\/sup>P NMR spectra were obtained from a BRUKER DRX-500 AVANCE instrument with CDCl3<\/sub> as an solvent at 500.1, 125.8, and 202.4 MHz respectively. Elemental analyses for C, H, N were performed using a Heraeus CHN-O-Rapid analyzer. In addition, the mass spectra were recorded on a GCMS-QP 5050A mass spectrometer operating at an ionization potential of 70 eV. (2H)-3-pyridazinone, 1-phenyl-3-pyrazolidinone, 2,4-thiazolinedione, Rhodanine,\u00a0 4,5,6,7-tetrahydroindazole, 3-methylpyrazole\u00a0 dialkyl acetylenedicarboxylates and triphenlphosphine, were purchsed from Fluka, (Buchs, Switzerland) and used without further purifications.<\/p>\n

General Procedures (Exemplified by 4a)<\/strong><\/p>\n

Preparation of dimethyl 2-( 3-pyridazinone-2-yl)-3-(triphenylphosphanylidene) butanedioate (4a).<\/strong><\/p>\n

To a magnetically stirred solution of triphenylphosphine (0.26 g or 1 mmol) and (2H)-3-pyridazinone (0.96 g or 1 mmol) in 10 mL of dry ethyl acetate was added, dropwise, a mixture of dimethyl acetylenedicarboxylate (0.14g or 1 mmol) in 5 mL of dry ethyl acetate over 10 min. After a few minutes stirring at room temperature, the product was filtered and washed with cold diethyl ether (3 \u00d7 5 mL).<\/p>\n

White powder, m.p 93-95\u00b0C, 0.46 g, yield 90%, IR (vmax<\/sub>, cm-1<\/sup>): 1733 and 1664 (C=O). 500 (M+<\/sup>,7), 438 (M-2OMe, 37), 382 (M-2CO2<\/sub>Me 46), 262 (PPh3<\/sub>, 80), 183 (PPh2<\/sub>, 48), 108 (PPh, 43), 77 (Ph, 35). Anal. calcd. for C28<\/sub>H25<\/sub>N2<\/sub>O5<\/sub>P (500): C, 67.17; H, 5.04; N, 5.60 %. Found: C, 67.21; H, 4.95; N, 5.67 %.<\/p>\n

Major isomer Z<\/em>-4a (60%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 3.14 and 3.72 (6H, 2s, 2OCH3<\/sub>), 5.64 (1H, d, 3<\/sup>J<\/em>PH <\/sub>= 17.0 Hz, P=C-CH<\/em>), 6.65-7.90 (18Haro, m, 3C6<\/sub>H5<\/sub> and C4<\/sub>H3<\/sub>N2<\/sub>O). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): \u03b4 42.75 (d, 1<\/sup>JPC <\/sub>= 126.8<\/em> Hz, P=C<\/em>), 49.34 and 52.30 (2s, 2OCH3<\/sub>), 63.72 (d, 2<\/sup>JPC<\/sub>=<\/strong>16.0<\/em> Hz, P-C-C<\/em>H), 108.89 (1C, C4<\/sub>H3<\/sub>N2<\/sub>O), 126.37 (d, 1<\/sup>JPC <\/sub>= 92.0 Hz, Cipso<\/sub>), 127.84 (d, 3<\/sup>JPC <\/sub>= 11.9 Hz, Cmeta<\/sub>), 132.19 (d, 4<\/sup>JPC <\/sub>= 2.1 Hz, \u00a0Cpara<\/sub>), 133.57 (1C, C4<\/sub>H3<\/sub>N2<\/sub>O), 133.28 (d, 2<\/sup>JPC <\/sub>= 9.0 Hz, Cortho<\/sub>), 147.55 and 162.13 (2C, C4<\/sub>H3<\/sub>N2<\/sub>O), 165.42 (d, 3<\/sup>J<\/em>PC <\/sub>= 15.7Hz, C=O), 171.57 (d, 2<\/sup>JPC <\/sub>= 13.5 Hz, P-C=C<\/em>). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 23.12 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Minor isomer E<\/em>-4a (40%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 3.61 and 3.66 (6H, 2s, 2OCH3<\/sub>), 5.75 (1H, d, 3<\/sup>JPH <\/sub>= 18.9 Hz, P=C-CH<\/em>), 6.65-7.90 (18Haro, m, 3C6<\/sub>H5<\/sub> and C4<\/sub>H3<\/sub>N2<\/sub>O). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): \u03b4 42.86 (d, 1<\/sup>J<\/em>PC <\/sub>= 136.0 Hz, P=C), 50.32 and 52.32 (2s, 2OCH3<\/sub>), 63.57 (d, 2<\/sup>JPC <\/sub>= 15.8 Hz, P-C-C<\/em>H), 108.93 (1C, C4<\/sub>H3<\/sub>N2<\/sub>O), 125.67 (d, 1<\/sup>J<\/em>PC <\/sub>= 92.1 Hz, Cipso<\/sub>), 128.27 (d, 3<\/sup>JPC <\/sub>= 12.0 Hz, Cmeta<\/sub>), 132.23 (d, 4<\/sup>JPC <\/sub>= 2.2 Hz, Cpara<\/sub>), 134.13 (1C, C4<\/sub>H3<\/sub>N2<\/sub>O), 133.59 (d, 2<\/sup>JPC <\/sub>= 9.8 Hz, Cortho<\/sub>), 147.63 and 163.14 (2C, C4<\/sub>H3<\/sub>N2<\/sub>O), 165.72 (d, 3<\/sup>J<\/em>PC <\/sub>=14.8 Hz, C=O), 169.83 (d, 2<\/sup>J<\/em>PC <\/sub>= 12.5 Hz, P-C=C<\/em>). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 22.97 (Ph3<\/sub>P+<\/sup>-C ).<\/p>\n

dimethyl-2-(1-phenyl-3-pyrazolidinone-2-yl)-3-(triphenylphosphanylidene)<\/strong> butanedioate <\/strong>(4b<\/strong>).<\/p>\n

white powder, m.p 166-168\u00b0C, 0.53g, yield 93%, IR (\u03c5max<\/sub>, cm-1<\/sup>) 1753 and 1676 (C=O). MS\u00a0 (m\/z<\/em>, %): 446 (M-2CO2<\/sub>Me, 17), 304 (M-PPh and Ph, 38), 262 (PPh3<\/sub>, 76), 183 (PPh2<\/sub>, 36), 108 (PPh, 43), 77 (Ph, 14). Anal. calcd. for C33<\/sub>H31<\/sub>N2<\/sub>O5<\/sub>P (566): C, 70.12; H,5.56; N, 5.02%. Found: C, 69.96; H, 5.48; N, 4.95%.<\/p>\n

Major isomer Z<\/em>-4b (68%): \u00a01<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4\u00a0 2.43(2H, m, H2<\/sub><\/em>C-CO), 3.20(3H, s, OCH3<\/sub><\/em>), 3.55(2H, m, H2<\/sub>C-N), 3.81 (3H, s, OCH3<\/sub><\/em>), 4.97 (1Hbro<\/sub>, P-C-CH<\/em>), 6.99\u20137.71 (20Harom<\/sub>, m, 4C6<\/sub>H5<\/sub>).\u00a0 13<\/sup>C NMR\u00a0 (125.8 MHz, CDCl3<\/sub>): \u03b4 29.65 and 30.03 (2C, C9<\/sub>H9<\/sub>N2<\/sub>O), 38.18 (d, 1<\/sup>JPC <\/sub>= 128.8 Hz, P=C), 49.68 and 52.08 (2s, 2OC<\/em>H3<\/sub>), 59.79 (d, 2<\/sup>JPC <\/sub>= 16.2 Hz, P-C-C<\/em>H), 116.56, 119.76, 123.03, 126.17 and 126.91 (5C, C9<\/sub>H9<\/sub>N2<\/sub>O), 126.54 (d, 1<\/sup>J<\/em>PC <\/sub>= 92.9 Hz, Cipso<\/sub>), 128.50 (d, 3<\/sup>JPC <\/sub>= 12.3 Hz, Cmeta<\/sub>), 131.85 (Cpara\u00ad<\/sub>), 132.07 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O), 133.73 (d, 2<\/sup>JPC <\/sub>= 9.8 Hz, Cortho<\/sub>), 170.43 (d, 3<\/sup>JPC <\/sub>= 16.8 Hz, C=O), 171.89 (d, 2<\/sup>JPC <\/sub>= 17.6 Hz, P-C=C<\/em>), 176.59 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O).\u00a0 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 23.56 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Minor isomer E<\/em>-4b (32%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 2.52(2H, m, H2<\/sub>C-CO), 3.44(2H, m, H2<\/sub>C-N), 3.74 and 3.79 (6H, 2s, 2OCH3<\/sub><\/em>), 4.93 (1Hbro<\/sub>, P-C-CH<\/em>), 6.99\u20137.71 (20Harom<\/sub>, m, 4C6<\/sub>H5<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): \u03b4 29.54 and 29.96 (2C, C9<\/sub>H9<\/sub>N2<\/sub>O),\u00a0 39.76 (d, 1<\/sup>JPC <\/sub>= 139.4 Hz, P=C), 52.01 and 52.27 (2s, 2OC<\/em>H3<\/sub>), 60.20 (d, 2<\/sup>JPC <\/sub>= 15.2 Hz, P-C-C<\/em>H), 116.52, 119.80, 123.07, 126.23 and 126.86 (5C, C9<\/sub>H9<\/sub>N2<\/sub>O), 126.17 (d, 1<\/sup>JPC <\/sub>= 92.0 Hz, Cipso<\/sub>), 128.60 (d, 3<\/sup>JPC <\/sub>= 11.8 Hz, Cmeta<\/sub>), 131.69 (Cpara\u00ad<\/sub>),\u00a0 132.15 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O), 133.64 (d, 2<\/sup>JPC <\/sub>= 10.0 Hz, Cortho<\/sub>), 172.02 (d, 3<\/sup>JPC <\/sub>= 14.3 Hz, C=O), 171.74 (d, 2<\/sup>JPC <\/sub>= 15.4 Hz,\u00a0 P-C=C<\/em>), 177.11 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 24.90 (Ph3<\/sub>P+<\/sup>-C ).<\/p>\n

Diethyl-2-(1-phenyl-3-pyrazolidinone-2-yl)-3-(triphenylphosphanylidene) butanedioate<\/strong> (4c<\/strong>).<\/p>\n

White powder, m.p 161-163\u00b0C, 0.54g, yield 91%, IR (\u03c5max<\/sub>, cm-1<\/sup>) 1748 and 1662\u00a0 (C=O). MS (m\/z<\/em>, %): 502 (M-2OEt , 50), 434 (M-PPh and OEt, 28), 330 (M-PPh3,<\/sub> 7), \u00a0<\/sub>\u00a0262 (PPh3,<\/sub> 85), 183 (PPh2<\/sub>, 83), 108 (PPh, 31). Anal. calcd. for C35<\/sub>H35<\/sub>N2<\/sub>O5<\/sub>P (594): C, 71.35; H, 6.05; N, 4.64%. Found: C, 70.71; H, 5.95; N, 4.71%.<\/p>\n

Major isomer Z<\/em>-4c (66%): \u00a01<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 0.36 and 1.27 (6H, 2t, 3<\/sup>JHH <\/sub>= 7.0 Hz,\u00a0 2OCH2<\/sub>CH3<\/sub><\/em>), 2.41(2H, m, H2<\/sub><\/em>C-CO), 3.48 and 3.54 (4H, 2m, 2ABX3<\/sub> system, 2OCH2<\/sub><\/em>CH3<\/sub>), 3.59(2H, m, H2<\/sub>C-N), 4.26 (1Hbro<\/sub>, P-C-CH<\/em>), 7.12-7.73 (20Harom<\/sub>, m, 4C6<\/sub>H5<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): \u03b4 13.96 and 14.13 (2s, 2OCH2<\/sub>C<\/em>H3<\/sub>), 29.61 and 30.09 (2C, C9<\/sub>H9<\/sub>N2<\/sub>O), 37.89 (d, 1<\/sup>JPC <\/sub>= 128.9 Hz, P=C), 57.45 and 58.05 ( 2S, 2OC<\/em>H2<\/sub>CH3<\/sub>), 59.98 (d, 2<\/sup>JPC <\/sub>= 14.8 Hz, P-C-C<\/em>H), 116.59, 119.80, 122.96, 126.35 and 127.08 (5C, C9<\/sub>H9<\/sub>N2<\/sub>O),\u00a0 126.27 (d, 1<\/sup>JPC <\/sub>= 92.0 Hz, Cipso<\/sub>), 128.35 (d,\u00a0 3<\/sup>Jpc <\/sub>= 12.1 Hz, Cmeta<\/sub>), 131.63 (Cpara<\/sub>), 132.07 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O), 133.88 (Cortho<\/sub>), 170.69 (d, 3<\/sup>JPC <\/sub>= 17.7 Hz, C=O), 171.19 (d, . 2<\/sup>JPC <\/sub>= 16.3 Hz, P-C=C<\/em>), 176.99 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O).31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 23.35 (Ph3<\/sub>P+<\/sup>-C)<\/p>\n

Minor isomer E<\/em>-4c (34%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 1.09 and 1.32 (6H, 2t, 3<\/sup>JHH <\/sub>= 7.2 Hz , 2OCH2<\/sub>CH3<\/sub><\/em>), 2.53(2H, m, H2<\/sub><\/em>C-CO), 3.41(2H, m, H2<\/sub>C-N),\u00a0 3.91 and 4.06 (4H, 2m, 2ABX3 <\/sub>system, 2OCH2<\/sub><\/em>CH3<\/sub>), 4.31 (1Hbro<\/sub>, P-C-CH<\/em>), 7.12-7.73 (20Harom<\/sub>, m, 4C6<\/sub>H5<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): \u03b4 14.13 and 14.73 (2s, 2OCH2<\/sub>C<\/em>H3<\/sub>), 29,53 and 30.01 (2C, C9<\/sub>H9<\/sub>N2<\/sub>O), 39.69 (d, 1<\/sup>J<\/em>PC <\/sub>=133.3 Hz, P=C), 58.01 and 58.39 (2s, 2OC<\/em>H2<\/sub>CH3<\/sub>),\u00a0 60.41 (d, 2<\/sup>JPC <\/sub>= 15.1 Hz, P-C-C<\/em>H), 116.51, 120.05, 123.20, 126.42 and 127.15 (5C, C9<\/sub>H9<\/sub>N2<\/sub>O), 126.72 (d, 1<\/sup>J<\/em>PC<\/sub>=91.8 Hz, Cipso<\/sub>), 128.54 (d, 3<\/sup>Jpc <\/sub>= 12.0 Hz, Cmeta<\/sub>), 129.19 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O), 131.76 (Cpara<\/sub>), 132.14 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O), 133.88 (Cortho<\/sub>), 169.98 (d, 3<\/sup>J<\/em>PC <\/sub>=16.4 Hz, C=O), 170.12 (d, 2<\/sup>JPC <\/sub>= 15.9 Hz, P-C=C<\/em>),177.26 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 23.52 (Ph3<\/sub>P+<\/sup>-C ).<\/p>\n

Di-tert-buthyl-2-(1-phenyl-3-pyrazolidinone-2-yl)-3-(triphenylphosphanylidene) butanedioate <\/strong>(4d<\/strong>).<\/p>\n

White crystals, m.p. 176-178 \u00baC, 0.62g, yield 96%; IR (\u03bdmax, cm-1): 1746 and 1671 (C=O). MS (m\/z<\/em>, %): 650 (M, 3), 386 (M-PPh3<\/sub>, 38),\u00a0 262 (PPh3<\/sub>, 79), 183 (PPh2<\/sub>, 43), 108 (PPh, 51). Anal. calcd. for C39<\/sub>H43<\/sub>N2<\/sub>O5<\/sub>P (650): C, 71.08; H, 6.72; N, 4.28%. Found: C, 71.56; H, 6.68; N, 4.31%.<\/p>\n

Major rotamer Z<\/em>-4d 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>), \u03b4H<\/sub> 0.80 and 1.49 (18H, 2s, 2OCMe<\/em>3), 2.50(2H, m, H2<\/sub>C-CO), 3.46(2H, m, H2<\/sub><\/em>C-N), 4.67 (1H, d, 3<\/sup>JPH <\/sub>= 17.4 Hz, P-C-CH<\/em>), 7.03-7.69 (20Harom<\/sub>, m, 4C6<\/sub>H5<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>), \u03b4 28.16 and 28.43 (2OCMe3<\/sub><\/em>), 29.76 and 30.12 (2C, C9<\/sub>H9<\/sub>N2<\/sub>O), 37.63 (d, 1<\/sup>JPC <\/sub>= 127.2 Hz, P=C), 60.79 (d, 2<\/sup>J<\/em>PC <\/sub>=14.9 Hz, P-C-C<\/em>H), 80.60 and 80.83 (2s, 2OC<\/em>Me3<\/sub>), 116.61, 119.36, 121.17, 122.75 and 123.66 (5C, C9<\/sub>H9<\/sub>N2<\/sub>O), 127.18 (d, 1<\/sup>JPC <\/sub>= 91.2 Hz, Cipso<\/sub>), 128.31 (d, 3<\/sup>JPC <\/sub>= 11.8 Hz, Cmeta<\/sub>), 131.56 (Cpara<\/sub>), 132.22 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O), 133.82 (d, 2<\/sup>JPC <\/sub>= 9.4 Hz, Cortho<\/sub>), 169.98(d, 3<\/sup>J<\/em>PC <\/sub>= 11.6 Hz, C=O), 171.03 (d, 2<\/sup>JPC <\/sub>= 11.7 Hz, P-C=C), 177.74 (1C, C9<\/sub>H9<\/sub>N2<\/sub>O).\u00a0 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4P<\/sub> 23.29 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Dimethyl -2-( 2,4-thiazolidinedione-2-yl)-3-(triphenylphosphanylidene) butaned- ioate<\/strong> (4e<\/strong>).<\/p>\n

White crystals, m.p. 95-97 \u00baC, 0.48g, yield 94%; IR (\u03bdmax, cm-1): 1739 and 1685, 1662 and 1610 (C=O); MS, (m\/z, %): 509 (M+<\/sup>, 1), 334 (M-C3<\/sub>H2<\/sub>O2<\/sub>NS and CO2<\/sub>Me, 29), 278 (M-3Ph, 69), 262 (PPh3<\/sub>, 83), 183 (PPh2<\/sub>, 86), 108 (PPh, 36). Anal. calcd. for C27<\/sub>H24<\/sub>NO6<\/sub>PS (521): C, 62.17; H, 4.64; N, 2.69 %. Found: C, 62.28; H, 4.60; N, 2.65%.<\/p>\n

Major rotamer Z<\/em>-4e (63%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>), \u03b4H <\/sub>3.11 and 3.70 (6H, 2s, 2OCH3<\/sub><\/em>), 3.75 (2H, dd, 2<\/sup>JHH <\/sub>= 16.0, S-CH2<\/sub>),\u00a0 4.78 (1H, d, 3<\/sup>JPH <\/sub>= 15.0 Hz, P-C-CH<\/em>), 7.45-7.70 (15Harom<\/sub>, m, 3C6<\/sub>H5<\/sub>); 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>), \u03b4C\u00a0 <\/sub>32.98 (1C, S-C<\/em>H2<\/sub>), 36.33 (d, 1<\/sup>JPC <\/sub>= 131.1 Hz, P=C), 49.08 and 52.88 (2OC<\/em>H3<\/sub>), 58.96 (d, 2<\/sup>JPC <\/sub>= 18.3 Hz, P-C-C<\/em>H), 126.71 (d, 1<\/sup>JPC <\/sub>= 91.7 Hz, Cipso<\/sub>), 128.87 (d, 3<\/sup>JPC <\/sub>= 10.7 Hz, Cmeta<\/sub>), 132.19 (Cpara<\/sub>), 133.60 (d, 2<\/sup>JPC <\/sub>= 9.8 Hz, Cortho<\/sub>), 170.29 (d, 3<\/sup>JPC <\/sub>= 12.3 Hz, C=O), 170.59 (d, 2<\/sup>JPC <\/sub>= 17.6 Hz, P-C=C<\/em>), 171.39 (1C, CH2<\/sub>–C<\/em>O), 172.01 (1C, S-C<\/em>O);\u00a0\u00a0 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4P<\/sub> 22.68 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Minor rotamer E<\/em>-4e (37%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>), \u03b4H<\/sub> 3.58 and 3.69 (6H, 2s, 2OCH<\/em>3<\/sub>), 3.73 (2H, dd, 2<\/sup>JHH <\/sub>= 16.1, S-CH2<\/sub>), 4.81 (1H, d, 3<\/sup>JPH <\/sub>= 15.9 Hz, P-C-CH<\/em>), 7.45-7.70 (15Harom<\/sub>, m, 3C6<\/sub>H5<\/sub>); 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>), \u03b4C<\/sub> 32.74 (1C, S-C<\/em>H2<\/sub>), 38.15 (d, 1<\/sup>JPC <\/sub>= 137.0 Hz, P=C), 50.53 and 52.64 (2 OC<\/em>H3<\/sub>), 58.54 (d, 2<\/sup>JPC <\/sub>= 17.6 Hz, P-C-C<\/em>H), 126.05 (d, 1<\/sup>JPC <\/sub>= 91.7 Hz, Cipso<\/sub>), 128.51 (d, 3<\/sup>JPC <\/sub>= 12.1 Hz, Cmeta<\/sub>), 132.16 (Cpara<\/sub>), 133.64 (d, 2<\/sup>JPC <\/sub>= 9.7 Hz, Cortho<\/sub>), 170.46 (d, 3<\/sup>JPC <\/sub>= 17.5 Hz, C=O), 171.01 (d, 2<\/sup>JPC <\/sub>= 18.7 Hz, P-C=C<\/em>), 171.27 (1C, CH2<\/sub>–C<\/em>O), 172.05 (1C, S-C<\/em>O);\u00a0\u00a0\u00a0 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4P<\/sub> 22.52 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Diethyl -2-(2,4-thiazolidinedione-2-yl)- 3-(triphenylphosphanylidene) <\/strong>butaned- ioate<\/strong> (4f<\/strong>).<\/p>\n

White crystals, m.p. 134-136 \u00baC, 0.49g, yield 91%; IR (\u03bdmax<\/sub>, cm-1<\/sup>): 1740, 1715, 1680 and 1636\u00a0 (C=O). MS, (m\/z, %): 391 (M-2CO2<\/sub>Et, 53), 275 (M-PPh3<\/sub>, 74), 262 (PPh3<\/sub>, 74), 183 (PPh2<\/sub>, 75), 108 (PPh, 37). Anal. calcd. for C29<\/sub>H28<\/sub>NO6<\/sub>PS (549): C, 63.36; H, 5.14; N, 2.55 %. Found: C, 63.30; H, 5.21; N, 2.49%.<\/p>\n

Major rotamer Z<\/em>-4f (71%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>), \u03b4H <\/sub>0.44 and 1.26 (6H, 2t, 3<\/sup>JHH <\/sub>= 6.8 Hz 2OCH2<\/sub>CH3<\/sub><\/em>), 3.68 (2H, dd, 2<\/sup>JHH <\/sub>= 16.5 Hz, S-CH2<\/sub><\/em>), 3.76 and 4.14 (4H, 2m, 2ABX3 <\/sub>systhem 2OCH2<\/sub><\/em>CH3<\/sub>), 4.79 (1H, d, 3<\/sup>JPH <\/sub>= 15.9 Hz, P-C-CH<\/em>), 7.48-7.73 (15Harom<\/sub>, m, 3C6<\/sub>H5<\/sub>); 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>), \u03b4C <\/sub>14.12 and 14.33 (2s, 2OCH2<\/sub>C<\/em>H3<\/sub>), 32.97 (1C, S-C<\/em>H2<\/sub>), 36.12 (d, 1<\/sup>JPC <\/sub>= 130.5 Hz, P=C), 57.62 and 59.14. ( 2S, 2OC<\/em>H2<\/sub>CH3<\/sub>), 59.78 (d, 2<\/sup>JPC <\/sub>= 18.2 Hz, P-C-C<\/em>H), 126.42 (d, 1<\/sup>JPC <\/sub>= \u00a091.8 Hz, Cipso<\/sub>), 128.73 (d, 3<\/sup>JPC <\/sub>= 11.2 Hz, Cmeta<\/sub>), 132.09 (Cpara<\/sub>), 133.64 (Cortho<\/sub>), 168.39 (d, 3<\/sup>JPC <\/sub>= 12.4 Hz, C=O), 169.77 (d, 2<\/sup>JPC <\/sub>= 11.6 Hz, P-C=C), 170.60 (1C, CH2<\/sub>–C<\/em>O), 170.67 (1C, S-C<\/em>O); 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4P<\/sub> 22.66 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Minor rotamer E<\/em>-4f (29%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>), \u03b4H<\/sub> 1.18 and 1.30 (6H, 2t, 3<\/sup>JHH <\/sub>= 7.2 Hz, 2OCH2<\/sub>CH3<\/sub><\/em>), 3.74 (2H, dd, 2<\/sup>JHH <\/sub>= 16.3 Hz, S-CH2<\/sub><\/em>),\u00a0 4.04 and 4.24 (4H, 2m, 2ABX3<\/sub>systhem 2OCH2<\/sub><\/em>CH3<\/sub>), 4.77 (1H, d, 3<\/sup>JPH <\/sub>= 18.0 Hz, P-C-CH<\/em>), 7.48-7.73 (15Harom<\/sub>, m, 3C6<\/sub>H5<\/sub>); 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>), \u03b4C<\/sub> 13.88 and 13.91 (2s, 2OCH2<\/sub>C<\/em>H3<\/sub>), 32.86 (1C, S-C<\/em>H2<\/sub>), 38.04 (d, 1<\/sup>JPC <\/sub>= 138.8 Hz, P=C), 57.67 and 59.36 (2s, 2OC<\/em>H2<\/sub>CH3<\/sub>),\u00a0 59.94 (d, 2<\/sup>JPC <\/sub>= 17.0 Hz, P-C-C<\/em>H), 126.37 (d, 1<\/sup>JPC <\/sub>= 92.1 Hz, Cipso<\/sub>), 128.50 (d, 3<\/sup>JPC <\/sub>= 12.1 Hz, Cmeta<\/sub>), 132.14 (Cpara<\/sub>), 133.60 (Cortho<\/sub>), 168.48 (d, 3<\/sup>JPC <\/sub>= 12.7 Hz, C=O), 169.67 (d, 2<\/sup>JPC <\/sub>= 14.8 Hz, P-C=C), 170.45 (1C, CH2<\/sub>–C<\/em>O), 170.85 (1C, S-C<\/em>O);\u00a0 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4P<\/sub> 22.71 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Di-tert-buthyl-2-(2,4-thiazolidinedione-1-yl)-3-(triphenylphosphanylidene) butanedioate <\/strong>(4g<\/strong>).<\/p>\n

White crystals, m.p. 133-135 \u00baC, 0.58g, yield 96%; IR (\u03bdmax, cm-1): 1737, 1729, 1665 and 1639 (C=O). ). MS, (m\/z, %): 343 (M-PPh3<\/sub>, 9), 276 (M-PPh2<\/sub> and 2OCMe3,<\/sub>38 ), 262 (PPh3<\/sub>, 75), 227 (M-PPh3<\/sub> and C3<\/sub>H2<\/sub>O2<\/sub>NS, 6), 183 (PPh2<\/sub>, 63), 108 (PPh, 26). Anal. calcd. for C33<\/sub>H36<\/sub>NO6<\/sub>PS (605): C, 65.42; H, 5.99; N, 2.31 %. Found: C, 65.51; H, 6.05; N, 2.35%.<\/p>\n

Major rotamer Z<\/em>-4g : 1H NMR (500.1 MHz, CDCl3<\/sub>), \u03b4H<\/sub> 0.94 and 1.54 (18H, 2s, 2OCMe<\/em>3), 3.72 (2H, dd, 2<\/sup>JHH <\/sub>= 16.9 Hz, S-CH2<\/sub><\/em>), 4.62 (1H, d, 3<\/sup>JPH <\/sub>= 17.3 Hz, P-C-CH<\/em>), 7.48-7.75 (15Harom<\/sub>, m, 3C6<\/sub>H5<\/sub>); 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>), \u03b4C<\/sub> 28.32 and 28.37 (2OCMe3<\/sub><\/em>), 32.82 (1C, S-C<\/em>H2<\/sub>), 36.13 (d, 1<\/sup>JPC <\/sub>= 130.8 Hz, P=C), 60.54 (d, 2<\/sup>JPC <\/sub>= 17.9 Hz, P-C-C<\/em>H), 77.17 and 81.26 (2s, 2OC<\/em>Me3<\/sub>), 127.51 (d, 1<\/sup>JPC <\/sub>= 91.7 Hz, Cipso<\/sub>), 128.64 (d, 3<\/sup>JPC <\/sub>= 11.7 Hz, Cmeta<\/sub>), 132.01(Cpara<\/sub>), 133.64 (d, 2<\/sup>JPC <\/sub>= 9.8 Hz, Cortho<\/sub>), 167.68 (d, 3<\/sup>JPC <\/sub>= 12.6 Hz, C=O), 168.66 (d, 2<\/sup>J<\/em>PC<\/sub>=13.3 Hz, P-C=C), 169.82 (1C, CH2<\/sub>–C<\/em>O), 170.74 (1C, S-C<\/em>O);\u00a0 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4P<\/sub> 23.15 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Dimethyl 2-(rhodanine-1-yl)-3-(triphenylphosphanylidene) butanedioate (4h).<\/strong><\/p>\n

white crystals, m.p 108-110 \u00b0C, 0.48 g , yield 90 % . IR (KBr) (vmax<\/sub>, cm-1<\/sup>): 1722, 1747 and 1623 (C=O). MS, (m\/z, %): 537 (M+<\/sup>, 6), 475 (M-2OCH3<\/sub>, 52), 419 (M-2CO2<\/sub>CH3<\/sub>, 36), 262 (PPh3<\/sub>, 85), 183 (PPh2<\/sub>, 61), 120 (C3<\/sub>H2<\/sub>NOS2<\/sub>, 29), 108 (PPh, 44), Anal. calcd. for C27<\/sub>H24<\/sub>NO5<\/sub>PS2<\/sub> (537): C, 60.31; H, 4.50; N, 2.67 %. Found: C, 60.25; H, 4.58; N, 2.75%.<\/p>\n

Major isomer Z<\/em>-4h (66%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 3.07 and 3.69 (6H, 2s, 2OCH3<\/sub>), 3.83 (2H, s, S-CH2<\/sub>), 5.39 (1H, d, 3<\/sup>JPH <\/sub>= 14.4 Hz, P=C-CH<\/em>), 7.47-7.72 (15Haro, m, 3C6<\/sub>H5<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): \u03b4 33.90 (1C, S-C<\/em>H2<\/sub>), 43.50 (d, 1<\/sup>JPC <\/sub>= 126.2 Hz, P=C<\/em>), 49.34 and 52.30 (2s, 2OCH3<\/sub>), 63.25 (d, 2<\/sup>JPC <\/sub>=<\/strong> 15.7 Hz, P-C-C<\/em>H), 126.30 (d, 1<\/sup>JPC <\/sub>= 92.1 Hz, Cipso<\/sub>), 128.57 (d, 3<\/sup>JPC <\/sub>= 12.2 Hz, Cmeta<\/sub>), 132.01 (d, 4<\/sup>JPC <\/sub>= 2.2 Hz, \u00a0Cpara<\/sub>), 133.47 (d, 2<\/sup>JPC <\/sub>= 8.9 Hz, Cortho<\/sub>), 165.4 (C=O), 170.60 (1C, CH2<\/sub>–C<\/em>O), 170.69 (1C, S-C<\/em>S); 171.59 (d, 2<\/sup>JPC <\/sub>= 12.5 Hz, P-C=C<\/em>). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 22.50 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Minor isomer E<\/em>-4h. (34%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 3.60 and 3.71 (6H, 2s, 2OCH3<\/sub>), 3.81 (2H, s, S-CH2<\/sub>), 5.51 (1H, d, 3<\/sup>JPH <\/sub>= 17.4 Hz, P=C-CH<\/em>), 7.47-7.72 (15Haro, m, 3C6<\/sub>H5<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): \u03b4 33.97 (1C, S-C<\/em>H2<\/sub>), 45.09 (d, 1<\/sup>J<\/em>PC <\/sub>=137.3 Hz, P=C), 51.36 and 52.47 (2s, 2OCH3<\/sub>), 63.78 (d, 2<\/sup>JPC <\/sub>= 15.9 Hz, P-C-C<\/em>H), 125.86 (d, 1<\/sup>J<\/em>PC<\/sub>=92.0 Hz, Cipso<\/sub>), 128.90 (d, 3<\/sup>JPC <\/sub>= 12.0 Hz, Cmeta<\/sub>), 132.29 (d, 4<\/sup>JPC <\/sub>= \u00a02.4 Hz, Cpara<\/sub>), 133.59 (d, 2<\/sup>JPC <\/sub>= 9.8 Hz, Cortho<\/sub>), 165.7 (C=O), 169.83 (d, 2<\/sup>JPC <\/sub>= 12.3 Hz, P-C=C<\/em>). 170.96 (1C, CH2<\/sub>–C<\/em>O), 171.16 (1C, S-C<\/em>S); 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 22.42 (Ph3<\/sub>P+<\/sup>-C ).<\/p>\n

Di-tert-butyl 2-(rhodanine-1-yl)-3-(triphenylphosphanylidene) butanedioate<\/strong> (4i).<\/strong><\/p>\n

White crystals, m.p 157-159 \u00baC, 0.58 g, yield 93 % . IR (vmax<\/sub>, cm-1<\/sup>): 1726, 1638 (C=O). MS, (m\/z, %): 621 (M+<\/sup>, 5), 507 (M-2CMe3<\/sub>, 34), 475 (M+<\/sup>-2OCMe3<\/sub>, 49), 262 (PPh3<\/sub>, 85), 183 (PPh2<\/sub>, 60), 108 (PPh, 51), Anal. calcd. for C33<\/sub>H36<\/sub>NO5<\/sub>PS2<\/sub> (621): C, 63.74; H, 5.84; N, 2.30 %. Found: C, 63.80; H, 5.91; N, 2.26%.<\/p>\n

Major isomer Z<\/em>-4i (87%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>), \u03b4 1.28 and 1.39 (18H, 2s, 2CMe<\/em>3<\/sub>), 3.73 (2H, d, S-CH2<\/sub>), 4.63 (1H, d, 3<\/sup>JPH <\/sub>= 16.6 Hz, P-C-CH<\/em>), 7.27-7.73 (15Haro, m, 3C6<\/sub>H5<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>), \u03b4 28.25 and 28.48 (2s, 2CMe<\/em>3<\/sub>), 34.12 (1C, S-C<\/em>H2<\/sub>), 40.92 (d, 1<\/sup>J<\/em>PC <\/sub>=126.9 Hz, P=C<\/em>), 64.33 (d, 2<\/sup>JPC <\/sub>= 14.7 Hz, P-C-C<\/em>H), 77.92 and 80.43 (2s, 2OC<\/em>Me3<\/sub>), 127.84 (d, 1<\/sup>JPC <\/sub>= 91. 6 Hz, Cipso<\/sub>), 128.31 (d, 3<\/sup>JPC <\/sub>= 12.2 Hz, Cmeta<\/sub>), 131.70 (Cpara<\/sub>), 133.99 (d, 2<\/sup>JPC <\/sub>= 9.7 Hz, Cortho<\/sub>), 167.85 (d, 3<\/sup>J<\/em>PC <\/sub>=12.2 Hz, C=O), 170.06 (d, 2<\/sup>J<\/em>PC <\/sub>=13.8 Hz, P-C=C<\/em>). 171.63 (1C, CH2<\/sub>–C<\/em>O), 171.97 (1C, S-C<\/em>S); 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 22.09 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Dimetyl-2-(<\/em><\/strong> 4,5,6,7-tetrahydroindazole-1-yl<\/em><\/strong>)-3-(<\/em><\/strong>triphenylphosphanylidene<\/em><\/strong>) butanedioate (4j).<\/em><\/strong><\/p>\n

white crystals, m.p 154-156\u00b0C, 0.45 g, yield 87 % . IR(KBr) (vmax<\/sub>, cm-1<\/sup>): 1753 and 1636 (2C=O). MS (m\/z, %): 526 (M+<\/sup>, 6), 501 (M+<\/sup>-CO2<\/sub>Me, 7), 467 (M+<\/sup>-CO2<\/sub>CH3<\/sub>,100), 405(M+<\/sup>-C7<\/sub>H9<\/sub>N2<\/sub>,65), 262 (PPh3<\/sub>, 80), 183 (PPh2<\/sub>, 100), 108 (PPh, 40), 77 (Ph, 15), 59 (CO2<\/sub>Me, 7). Anal. calcd. for C31<\/sub>H31<\/sub>N2<\/sub>O5<\/sub>P (526): C, 70.69; H, 5.94; N, 5.32 %. Found: C, 70.63; H, 5.98; N, 5.38%.<\/p>\n

Major isomer Z<\/em>-4j (52%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 1.73 and 2.68 (8H, m, 4CH2<\/sub>), 3.14 and 3.72 (6H, 2s, 2OCH3<\/sub>), 4.90 (1H, d, 3<\/sup>JPH <\/sub>= 16.7 Hz, P=C-CH<\/em>), 7.45-7.72 (16Haro, m, 3C6<\/sub>H5<\/sub> and C7<\/sub>H9<\/sub>N2<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): 20.87, 23.23 and 23.54 (4 CH2<\/sub>), 43.72 (d, 1<\/sup>JPC <\/sub>= 128.2 Hz, P=C), 49.26 and 52.35 (2s, 2OCH3<\/sub>), 64.54 (d, 2<\/sup>JPC <\/sub>= 15.0 Hz, P=C-C<\/em>H), 115.45 (1C, N-C=C<\/em>), 126.44 (d, 1<\/sup>JPC <\/sub>= 92.9 Hz, Cipso<\/sub>), 128.49 (d, 3<\/sup>JPC <\/sub>= 12.1 Hz, Cmeta<\/sub>), 131.92 (Cpara<\/sub>), 133.40 (1C, N-N=C), 133.64 (d, 2<\/sup>JPC <\/sub>= 9.9 Hz, Cortho<\/sub>), 146.90 (1C, N-C<\/em>=C), 165.37 (C=O), 172.59 (d, 2<\/sup>JPC <\/sub>= 13.0 Hz, P-C=C<\/em>). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 24.18 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Minor isomer E<\/em>-4j (48%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 1.73 and 2.68 (8H, m, 4CH2<\/sub>), 3.61 and 3.72 (6H, 2s, 2OCH3<\/sub>), 4.93 (1H, d, 3<\/sup>JPH <\/sub>= 18.3 Hz, P=C-CH<\/em>), 7.45-7.72 (16H, m, 3C6<\/sub>H5 <\/sub>and C7<\/sub>H9<\/sub>N2<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): 21.94, 22.90 and 23.63 (4 CH2<\/sub>), 43.94 (d, 1<\/sup>JPC <\/sub>= 133.8 Hz, P=C), 52.22 and 52.53 (2s, 2OCH3<\/sub>), 63.93 (d, 2<\/sup>JPC <\/sub>= 16.3 Hz, P=C-C<\/em>H), 115.13 (1C, N-C<\/em>=C), 125.93 (d, 1<\/sup>JPC <\/sub>= 82.4 Hz, Cipso<\/sub>), 128.81 (d, 3<\/sup>JPC <\/sub>=\u00a0 12.3 Hz, Cmeta<\/sub>), 131.92 (Cpara<\/sub>), 133.19 (1C, N-N=C), 133.64 (d, 2<\/sup>JPC <\/sub>= 9.9 Hz, Cortho<\/sub>), 147.43 (1C, N-C<\/em>=C), 165.68 (C=O), 169.78 (d, 2<\/sup>JPC <\/sub>= 12.1 Hz, P-C=C<\/em>), 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 23.06 (Ph3<\/sub>P+<\/sup>-C ).<\/p>\n

Dimethyl 2-(3-methylpyrazole-1-yl)-3-(triphenylphosphanylidene) butanedioate (4k).<\/strong><\/p>\n

White powder, m.p 183-144\u00b0C, 0.46 g, yield 94%, IR (vmax<\/sub>, cm-1<\/sup>): 1755 and 1638 (C=O). MS (m\/z, %): 486 (M+<\/sup>, 9), 423 (M+<\/sup>-CO2<\/sub>Me, 100), 405 (M+<\/sup>-C4<\/sub>H5<\/sub>N2<\/sub>, 22), 262 (PPh3<\/sub>, 35), 183 (PPh2<\/sub>, 50), 108 (PPh, 20), 77 (Ph, 8). Anal. calcd. for C28<\/sub>H27<\/sub>N2<\/sub>O4<\/sub>P (486): C, 69.11; H, 5.60; N, 5.76 %. Found: C, 68.97; H, 5.65; N, 5.80 %.<\/p>\n

Major isomer Z<\/em>-4k (55%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 2.17 (3H, s, CH3<\/sub>), 3.20 and 3.72 (6H, 2s, 2OCH3<\/sub>), 4.91 (1H, d, 3<\/sup>JPH <\/sub>= 16.6 Hz, P=C-CH<\/em>), 7.28-7.95 (17Haro, m, 3C6<\/sub>H5<\/sub> and C4<\/sub>H5<\/sub>N2<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): \u03b4 13.52 (s, CH3<\/sub>), 43.76 (d, 1<\/sup>JPC <\/sub>= 127.7 Hz, P=C<\/em>), 49.34 and 52.30 (2s, 2OCH3<\/sub>), 64.52 (d, 2<\/sup>JPC <\/sub>= <\/strong>15.9 Hz, P-C-C<\/em>H), 104.97 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 126.30 (d, 1<\/sup>JPC <\/sub>= 92.1 Hz, Cipso<\/sub>), 128.57 (d, 3<\/sup>JPC <\/sub>= 12.2 Hz, Cmeta<\/sub>), 132.01 (d, 4<\/sup>JPC <\/sub>= 2.2 Hz, \u00a0Cpara<\/sub>), 132.13 (1C, C4<\/sub>H4<\/sub>N2<\/sub>), 133.47 (d, 2<\/sup>JPC <\/sub>= 8.9 Hz, Cortho<\/sub>), 146.50 (N-N=C), 165.4 (C=O), 172.50 (d, 2<\/sup>JPC <\/sub>=12.6 Hz, P-C=C<\/em>). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 24.08 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Minor isomer E<\/em>-4k\u00a0<\/strong>(45%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 2.20 (3H, s, CH3<\/sub>), 3.61 and 3.71(6H, 2s, 2OCH3<\/sub>), 4.95 (1H, d, 3<\/sup>JPH <\/sub>= 18.2 Hz, P=C-CH<\/em>), 7.28-7.95 (17Haro, m, 3C6<\/sub>H5<\/sub> and C4<\/sub>H5<\/sub>N2<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): \u03b4 11,98 (s, CH3<\/sub>), 44.04 (d, 1<\/sup>JPC <\/sub>= 138.0 Hz, P=C), 50.32 and 52.32 (2s, 2OCH3<\/sub>), 63.57 (d, 2<\/sup>JPC <\/sub>= 15.8 Hz, P-C-C<\/em>H), 104.77 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 125.67 (d, 1<\/sup>JPC <\/sub>= 92.2 Hz, Cipso<\/sub>), 128.84 (d, 3<\/sup>JPC <\/sub>= 12.1 Hz, Cmeta<\/sub>), 132.13 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 132.29 (d, 4<\/sup>JPC <\/sub>= 2.4 Hz, Cpara<\/sub>), 133.59 (d, 2<\/sup>JPC <\/sub>= 9.8 Hz, Cortho<\/sub>), 147.00 (N-N=C), 165.7 (C=O), 169.83 (d, 2<\/sup>JPC <\/sub>= 12.3 Hz, P-C=C<\/em>). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 24.84 (Ph3<\/sub>P+<\/sup>-C ).<\/p>\n

Diethyl 2-(3-methylpyrazole-1-yl)-3-(triphenylphosphanylidene) butanedioate<\/strong> (4l).<\/strong><\/p>\n

white crystals, m.p 147-149\u00b0C, 0.47 g , yield 92% . IR(KBr) (vmax<\/sub>, cm-1<\/sup>): 1757 and 1635 (C=O). MS (m\/z, %): 514 (M+<\/sup>, 3), 441 (M+<\/sup>-CO2<\/sub>Et, 100), 262 (PPh3<\/sub>, 42), 183 (PPh2<\/sub>, 44), 108 (PPh, 21), 77 (Ph, 8). Anal. calcd. for C30<\/sub>H31<\/sub>N2<\/sub>O4<\/sub>P (514): C, 70.00; H, 6.08; N, 5.44 %. Found: C, 70.38; H, 6.13; N, 5.49 %.<\/p>\n

Major isomer Z<\/em>-4l (63%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 0.48 and 1.23 (6H, 2t, 3<\/sup>JHH <\/sub>= 7.1Hz, 2OCH2<\/sub>CH3<\/sub><\/em>), 2.17 (3H, s, CH3<\/sub>), 3.75 and 4.10 (4H, 2m, 2ABX3 <\/sub>system, 2OCH2<\/sub><\/em>CH3<\/sub>), 4.90 (1H, d, 3<\/sup>JPH <\/sub>= 16.8 Hz, P-C-CH<\/em>), 7.20-7.97 (17Haro, m, 3C6<\/sub>H5<\/sub> and C4<\/sub>H5<\/sub>N2<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): 13.56 (s, CH3<\/sub>) 13.56 and 14.21 (2OCH2<\/sub>CH3<\/sub><\/em>), 43.40 (d, 1<\/sup>JPC <\/sub>= 127.6 Hz, P=C<\/em>), 57.75 and 61.09 (2s, 2OCH2<\/sub><\/em>CH3<\/sub>), 64.53 (d, 2<\/sup>JPC <\/sub>= 16.6 Hz, P-C-C<\/em>H), 104.80 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 126.62 (d, 1<\/sup>JPC <\/sub>= 92.1 Hz, Cipso<\/sub>), 128.70 (d, 3<\/sup>JPC <\/sub>= 12.1 Hz, Cmeta<\/sub>), 132.21 (Cpara<\/sub>), 133.61 (d, 2<\/sup>JPC <\/sub>= 9.8 Hz, Cortho<\/sub>), 133.67 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 146.13 (1C, N-N=C), 169.21 (d, 3<\/sup>JPC <\/sub>= 12.8 Hz,C=O), 171.68 (d, 2<\/sup>JPC <\/sub>= 12.3 Hz, P-C=C<\/em>). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 24.09 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Minor isomer E<\/em>-4l (37%): \u00a01<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>): \u03b4 1.18 and 1.30 (6H, 2t, 3<\/sup>JHH<\/sub>=7.1 Hz, 2OCH2<\/sub>CH3<\/sub><\/em>), 2.20 (3H, s, CH3<\/sub>), 4.75 and 4.20 (4H, 2m, 2ABX3<\/sub>system, 2OCH2<\/sub><\/em>CH3<\/sub>), 4.91 (1H, d, 3<\/sup>JPH <\/sub>= 18.1 Hz, P-C-CH<\/em>), 7.20-7.97 (17Haro, m, 3C6<\/sub>H5<\/sub> and C4<\/sub>H5<\/sub>N2<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>): 13.11 (s, CH3<\/sub>), 13.99 and 14.84 (2OCH2<\/sub>CH3<\/sub>), 43.85 (d, 1<\/sup>JPC <\/sub>= 135.6 Hz, P=C), 58.39 and 61.09 (2s, 2OCH2<\/sub><\/em>CH3<\/sub>), 63.86 (d, 2<\/sup>JPC <\/sub>= 16.3 Hz, P-C-C<\/em>H), 104.64 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 125.96 (d, 1<\/sup>JPC <\/sub>= 92.7 Hz, Cipso<\/sub>), 128.70 (d, 3<\/sup>JPC <\/sub>= 12.1 Hz, Cmeta<\/sub>), 132.21 (Cpara<\/sub>), 133.61 (d, 2<\/sup>JPC <\/sub>= 9.8 Hz, Cortho<\/sub>), 133.67 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 146.61 (1C, N-N=C), 169.99 (d, 3<\/sup>JPC <\/sub>= 12.8 Hz,C=O), 171.53 (d, 2<\/sup>JPC <\/sub>= 10.6 Hz, P-C=C). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 24. 95 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Di-tert-butyl 2-(3-methylpyrazole-1-yl)-3-(triphenylphosphanylidene) butanedioate<\/strong> (4m)<\/strong>.<\/strong><\/em><\/p>\n

White crystals, m.p 175-177 \u00baC, 0.55 g, yield 96% . IR (vmax<\/sub>, cm-1<\/sup>): 1749, 1642 (C=O). MS, (m\/z, %): 570 (M+<\/sup>, 10), 469 (M+<\/sup>-CO2<\/sub>CMe3<\/sub>, 65), 287 (M+<\/sup>– PPh3<\/sub>-C-CH,85), 262 (PPh3<\/sub>, 50), 183 (PPh2<\/sub>, 55), 108 (PPh, 23), 77 (Ph, 5), 57 (CMe3<\/sub>, 33). Anal. calcd. for C34<\/sub>H39<\/sub>N2<\/sub>O4<\/sub>P (570): C, 71.54; H, 6.89; N, 4.91 %. Found: C, 71.60; H, 6.92; N, 4.89 %.<\/p>\n

Major isomer Z<\/em>-4m (57%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>), \u03b4 0.95 and 1.50 (18H, 2s, 2CMe<\/em>3<\/sub>), 2.15 (3H, s, CH3<\/sub>), 4.96 (1H, d, 3<\/sup>JPH <\/sub>= 17.3 Hz, P-C-CH<\/em>), 6.60-8.00 (17Haro, m, 3C6<\/sub>H5<\/sub> and C4<\/sub>H5<\/sub>N2<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>), \u03b4 13.56 (s, CH3<\/sub>), 28.18 and 28.37 (2s, 2CMe<\/em>3<\/sub>), 43.21 (d, 1<\/sup>JPC <\/sub>= 127.1 Hz, P=C<\/em>), 65.24 (d, 2<\/sup>JPC <\/sub>= 16.74 Hz, P-C-C<\/em>H), 77.89 and 80.54 (2s, 2OC<\/em>Me3<\/sub>), 104.68 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 127.4 (d, 1<\/sup>JPC <\/sub>= 92.0 Hz, Cipso<\/sub>), 128.51 (d, 3<\/sup>JPC <\/sub>= 12.3 Hz, Cmeta<\/sub>), 132.00 (Cpara<\/sub>), 133.71 (d, 2<\/sup>JPC <\/sub>= 9.6 Hz, Cortho<\/sub>), 145.85 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 168.65 (d, 3<\/sup>JPC <\/sub>= 12.2 Hz, C=O), 170.39 (d, 2<\/sup>JPC <\/sub>= 13.3 Hz, P-C=C<\/em>). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 24.91 (Ph3<\/sub>P+<\/sup>-C).<\/p>\n

Minor isomer E<\/em>-4m (43%): 1<\/sup>H NMR (500.1 MHz, CDCl3<\/sub>), \u03b4 1.46 and 1.48 (18H, 2s, 2CMe<\/em>3<\/sub>), 2.18 (3H, s, CH3<\/sub>), 4.99 (1H, d, 3<\/sup>JPH <\/sub>= 16.9 Hz, P-C-CH<\/em>), 6.60-8.00 (17Haro, m, 3C6<\/sub>H5<\/sub> and C4<\/sub>H5<\/sub>N2<\/sub>). 13<\/sup>C NMR (125.8 MHz, CDCl3<\/sub>), \u03b4 11.01 (s, CH3<\/sub>), 28.12 and 28.45 (2s, 2CMe<\/em>3<\/sub>), 43.55 (d, 1<\/sup>JPC <\/sub>= 138.1 Hz, P=C<\/em>), 64.20 (d, 2<\/sup>JPC <\/sub>=15.08 Hz, P-C-C<\/em>H), 77.93 and 80.42 (2s, 2OC<\/em>Me3<\/sub>), 104.39 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 127.27 (d, 1<\/sup>JPC <\/sub>= 92.1 Hz, Cipso<\/sub>), 128.51 (d, 3<\/sup>JPC <\/sub>= 12.3 Hz, Cmeta<\/sub>), 132.00 (Cpara<\/sub>), 133.93 (d, 2<\/sup>JPC <\/sub>= 9.8 Hz, Cortho<\/sub>), 146.41 (1C, C4<\/sub>H5<\/sub>N2<\/sub>), 168.65 (d, 3<\/sup>JPC <\/sub>= 12.2 Hz, C=O), 170.39 (d, 2<\/sup>JPC <\/sub>= 13.3 Hz,P-C=C). 31<\/sup>P NMR (202.4 MHz, CDCl3<\/sub>): \u03b4 24.47(Ph3<\/sub>P+<\/sup>-C).<\/p>\n

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