Steric and electronic effect of secondary phosphines in reactions with cyclopalladated complexes

摘要: Abstract Reactions of secondary phosphines HPR1R2 [R1 = R2 = p-MeOC6H4 (b), p-CF3C6H4 (c), mesityl (Mes, d) or 1-adamantyl (Ad, e); R1 = t-Bu, R2 = Ph (f)] with cyclopalladated complexes (CPCs) derived from N,N-dimethylbenzylamine (1), l -fenchone methyloxime (3), (S)-N,N-dimethylbenzylamine (9), and (S)-di-2,4-tert-butyloxazoline (11) were studied. Phosphination the ligands in 1 3 was observed using either 4.5:1 9:1 molar ratios HPAr2 (b,c) to CPC presence 9 equiv. Cs2CO3. The corresponding N,P 2b,c 4b,c isolated 44–59% yields. sterically hindered HPMes2 CPCs provided phosphination product, 4d′, only for latter complex (32% yield). Attempts synthesize HPAd2 unsuccessful palladacycle. Major products reactions bulky rare mononuclear 5d,e (up 90%) 7d,e (81 86%) an ancillary phosphine ligand dinuclear monophosphido, monochloro-bridged 6d (98%) 8d,e (69% 66%) depending on HPR2:CPC ratio used. Enantiopure reacted racemic HPt-BuPh give a single diastereomer product 4f 12% yield. use transformations two other enantiopure CPCs, 11, form C Pt-BuPh bond unsuccessful. Instead, these 11f 13f 32 76% yield, respectively. Analysis 1H, 13C{1H} 31P{1H} NMR data all new Pd(II) is provided. An X-ray crystallographic study 7d proved its trans-N,P geometry.