Palladium/NHC (NHC = <i>N</i>-Heterocyclic Carbene)-Catalyzed B-Alkyl Suzuki Cross-Coupling of Amides by Selective N–C Bond Cleavage
作者:Guangrong Meng、Michal Szostak
DOI:10.1021/acs.orglett.8b02911
日期:2018.11.2
carbene)-catalyzed, direct cross-coupling between B-sp3-alkyl reagents and activated amides by N–C(O) cleavage is reported. Palladium-NHC precatalysts promote chemoselective alkylations of amides that are inaccessible by applying strong organometallic reagents. Various amides, including challenging primary amides after direct and site-selective N,N-di-Boc activation, are compatible with this method. The
据报道,通过N-C(O)裂解,钯-NHC(NHC = N-杂环卡宾)具有高度化学选择性,催化B-sp 3-烷基试剂与活化酰胺之间的直接交叉偶联。钯-NHC预催化剂可促进酰胺的化学选择性烷基化,这是通过使用强有机金属试剂无法实现的。各种酰胺,包括直接和位点选择性的N,N -di-Boc活化后具有挑战性的伯酰胺,都与此方法兼容。顺序C(sp 2)–C(sp 2)/ C(sp 2)–C(sp 3)证明了这种温和协议的潜力)交叉偶联,该偶联使用源自共同伯酰胺键的di-Boc酰胺。该方法在B-烷基-Suzuki交叉偶联中提供了空气和水分稳定,轮廓分明且高反应性的Pd-NHC预催化剂的罕见实例。