Sterics versus Electronics: Regioselective Cross-Coupling of Polybrominated Thiophenes
作者:Chad M. Amb、Seth C. Rasmussen
DOI:10.1002/ejoc.200701148
日期:2008.2
Methods for the regioselective cross-coupling of 2,3,5-tribromothiophene have been developed in which selective aryl–aryl coupling occurs at the 5-position with yields up to 63 %. The difference in reactivity of the α- and β-positions then allows sequential regioselective couplings first at the 2-position, followed by the 3-position. Such regioselective cross-coupling allows unprecedented control in
已经开发了 2,3,5-三溴噻吩的区域选择性交叉偶联方法,其中选择性芳基-芳基偶联发生在 5 位,产率高达 63%。α 位和 β 位反应性的差异允许顺序区域选择性偶联首先在 2 位,然后是 3 位。这种区域选择性交叉偶联允许对三官能化噻吩的生成进行前所未有的控制。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)