Altman Ryan A, Hyde Alan M, Huang Xiaohua, Buchwald Stephen L
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
J Am Chem Soc. 2008 Jul 23;130(29):9613-20. doi: 10.1021/ja803179s. Epub 2008 Jun 28.
In the cross-coupling reactions of unprotected oxindoles with aryl halides, Pd- and Cu-based catalyst systems displayed orthogonal chemoselectivity. A Pd-dialkylbiarylphosphine-based catalyst system chemoselectively arylated oxindole at the 3 position, while arylation occurred exclusively at the nitrogen using a Cu-diamine-based catalyst system. Computational examination of the relevant L1Pd(Ar)(oxindolate) and diamine-Cu(oxindolate) species was performed to gain mechanistic insight into the controlling features of the observed chemoselectivity.
在未保护的羟吲哚与芳基卤化物的交叉偶联反应中，钯基和铜基催化剂体系表现出正交化学选择性。基于钯-二烷基联芳基膦的催化剂体系在3位对羟吲哚进行化学选择性芳基化，而使用基于铜-二胺的催化剂体系时，芳基化仅发生在氮原子上。对相关的L1Pd(Ar)(羟吲哚盐)和二胺-铜(羟吲哚盐)物种进行了计算研究，以深入了解所观察到的化学选择性的控制特征。
