Palladacycles bearing tridentate CNS-type benzamidinate ligands as catalysts for cross-coupling reactions
作者:Wei-Chi Wang、Kuo-Fu Peng、Ming-Tsz Chen、Chi-Tien Chen
DOI:10.1039/c2dt11097k
日期:——
Three pendant benzamidines, [Ph–C(NC6H5)–NH(E)}] [E = –(CH2)2SMe (1); –(CH2)2StBu (2); –o-C6H4SMe (3)], are described. Reactions of 1, 2 or 3 with one molar equivalent of Pd(OAc)2 in CH2Cl2 give the palladacyclic complexes, [Ph–C–NH(η1-C6H4)}N(E)}]Pd(OAc) [E = –(CH2)2SMe (4); –(CH2)2StBu (5); –o-C6H4SMe (6)], as mononuclear palladium complexes respectively. A minor product described as 5′, [Ph–C–N(C6H5)}–N(CH2)2StBu}]Pd(OAc)}2, was isolated as benzamidinate-bridged dinuclear palladium complex upon recrystallizing from Et2O/hexane solution. Treatment of 1, 2 or 3 with one molar equivalent of PdCl2 in the presence of NEt3 in CH2Cl2 gives the palladacyclic complexes, [Ph–C–NH(η1-C6H4)}N(E)}]PdCl [E = –(CH2)2SMe (7); –(CH2)2StBu (8); –o-C6H4SMe (9)], as mononuclear palladium complexes respectively. The crystal and molecular structures are reported for compounds 5, 5′ and 6–8. The application of these palladacyclic complexes to the Suzuki and Heck coupling reactions was examined.
描述了三种悬挂式苯氨基脲,[Ph–C(NC6H5)–NH(E)}] [E = –(CH2)2SMe (1); –(CH2)2StBu (2); –o-C6H4SMe (3)]。1、2或3与一摩尔当量的Pd(OAc)2在CH2Cl2中反应,分别生成单核钯配合物,palladacyclic complexes,[Ph–C–NH(η1-C6H4)}N(E)}]Pd(OAc) [E = –(CH2)2SMe (4); –(CH2)2StBu (5); –o-C6H4SMe (6)]。一种小产物被描述为5′,[Ph–C–N(C6H5)}–N(CH2)2StBu}]Pd(OAc)}2,在从Et2O/己烷溶液重结晶后,作为苯氨基脲桥接的双核钯配合物被分离。1、2或3与一摩尔当量的PdCl2在NEt3存在下于CH2Cl2中处理,分别生成单核钯配合物,palladacyclic complexes,[Ph–C–NH(η1-C6H4)}N(E)}]PdCl [E = –(CH2)2SMe (7); –(CH2)2StBu (8); –o-C6H4SMe (9)]。报告了化合物5、5′和6-8的晶体及分子结构。对这些palladacyclic配合物在铃木反应和赫克耦合反应中的应用进行了研究。