Gold(I) and Palladium(II) Complexes Containing the Functionalized Ylides Triarylphosphonium Cyanomethylide or 2-Cyanoethylide (R3P=CHR′, R′=CN, CH2CN)

• Published in: Helvetica chimica acta Vol. 82; no. 8; pp. 1202 - 1210
• Main Authors: Vicente, José, Chicote, María-Teresa, Lagunas, María-Cristina
• Format: Journal Article
• Language: English
• Published: Basel Verlag Helvetica Chimica Acta 04.08.1999
• ISSN: 0018-019X; 1522-2675
• DOI: 10.1002/(SICI)1522-2675(19990804)82:8<1202::AID-HLCA1202>3.0.CO;2-G

The coordination properties of ylides R3P=CHCN and R3P=CHCH2CN were studied. Ylide R3P=CHCN reacts with [AuCl(tht)] (molar ratio 1 : 1, tht=tetrahydrothiophene) to give [AuCl{CH(PPh3)CN}] (1). Dinuclear complexes [(AuL)2{μ‐C(PR3)CN}]ClO4⋅nH2O (n=1, L=PPh3, R=Ph (2a) or Tol (=4‐MeC6H4) (2b); n=0, R=Tol, L=P(pmp)3 (2c; pmp=4‐MeOC6H4 or AsPh3 (2d)) are the products of reactions between phosphonium salts (R3PCH2CN)ClO4 (R=Ph or Tol) and [Au(acac)L] (molar ratio 1 : 3, L=PPh3 or P(pmp)3; acacH=acetylacetone). The reaction of [Au(acac)PPh3] with (Ph3PCH2CH2CN)ClO4 (Au/P 2 – 5) gives the mononuclear complex [Au{CH(PPh3)CH2CN}(PPh3)]ClO4⋅0.5 H2O (3). Complexes 2b or 2c react with [Au(acetone)L]ClO4 (molar ratio 1 : 1, L=PPh3 or P(pmp)3), prepared in situ from [AuCl(L)] and AgClO4 in acetone, to give the corresponding trinuclear derivatives [(AuL)2{μ3‐{C(PTol3)CN}(AuL)}](ClO4)2 (L=PPh3 (4a) or P(pmp)3 (4b)]. We attempted unsuccessfully to prepare single crystals of 4a or 4b or of the triflate salt [{Au(PPh3)}2{μ3‐{C(PTol3)CN}(AuPPh3)}](TfO)2⋅H2O (4a′), obtained by reacting 4a with 2 equiv. of KCF3SO3. In complexes 2 and 4, two new types of coordination of the ylides R3P=CHCN are present. Attempts to coordinate three AuL groups to the N‐atom of (R3PCCN)− induced by aurophilicity (see A and B) were unsuccessful. The reaction between PdCl2 and R3P=CHCN (molar ratio 1 : 2) gives trans‐[PdCl2{CH(PTol3)CN}2] (5).