Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
J Org Chem. 2014 May 2;79(9):4161-6. doi: 10.1021/jo500355k. Epub 2014 Apr 18.
A series of phosphine-ligated palladium precatalysts based on N-methyl- and N-phenyl-2-aminobiphenyl have been developed. Substitution at the nitrogen center prevents the presence of traces of aminobiphenyls that contain a free -NH2 group from contaminating cross-coupling products. These precatalysts produce N-substituted carbazoles upon activation, which cannot consume starting materials. These precatalysts were efficiently generated from 2-aminobiphenyl with minimal purification and found to be highly effective in Suzuki-Miyaura and C-N cross-coupling reactions.
已开发出一系列基于 N-甲基-和 N-苯基-2-氨基联苯的膦配位钯前催化剂。氮中心的取代可防止含有游离-NH2 基团的联苯胺痕量存在污染交叉偶联产物。这些前催化剂在活化后生成 N-取代咔唑,不能消耗起始原料。这些前催化剂可从 2-氨基联苯高效生成,无需进行最小限度的纯化,并且在 Suzuki-Miyaura 和 C-N 交叉偶联反应中非常有效。