New ylide-, alkynyl-, and mixed alkyny/ylide-gold(I) complexes

Reactions of AuCl(tht) (tht = tetrahydrothiophene) with various ylides in equimolar amounts give the complexes [AuCl(ylide)]X-n (n = 0, ylide = C(PPh3)(2) (1a), 4-MeC6H4SO2-CHPPh3 (1b); n = 1, X = TFO, ylide = [HC(PPh3)(2)](+) (2)) and 1(AuCl)(2){mu-C(PPh3)(2)}] (3) when using a 2:1 molar ratio. The complex la reacts (i) with Tl(acac) to give [Au(acac)f C(PPh3)(2)] (4) and (ii) with terminal alkynes (with or without added Et3N) to give [HC(PPh3)(2)] [Au-(Cequivalent toCC(6)H(4)R-4)C] (R = H (5a), CN (5b), OMe (5c), NO2 (5d)) instead of the desired complexes [Au(CdropCC(6)H(4)R-4){C{PPh3}(2)]. These complexes (R = H (6a), CN (6b), OMe (6c), NO2 (6d), C drop CPh (6e)) were prepared by the reaction of [Au(acac) {C(PPh3)(2)}] (4) with a large excess of alkynes (ca. 1:25-30). Complex 1b reacts with terminal alkynes in the presence of Et3N differently from la, giving the complexes [Au(CdropCC(6)H(4)R-4){CH(PPh3){S(O)(2)C6H4Me-4}}] (R = H (7a), NC (7b), OMe (7c), NO2 (7d), C drop CPh (7e)). The reaction of PPN[Au(acac)(2)] with the phosphonium salt [H2C(PPh3)(2)](TfO)(2) or [4-MeC6H4S(O)(2)CH2PPh3]TfO in 1:2 stoichiometry afforded the cationic complex [Au(ylide)(2)](TfO)(n), where the ylide is [HC(PPh3)(2)](+) (n = 3, 8a) or 4-MeC6H4S(O)(2)CHPPh3 (n = 1, 8b), respectively. The crystal structures of [4-MeC6H4S(O)(2)CH2PPh3]TfO, 1b(.)0.5CH(2)Cl(2), 3(.)3CH(2)Cl(2),5a, 5c, 6d(.)THF, and 8b have been determined.