Copper-mediated Regioselective C–H Cyanation of Phenols with Assistance of Bipyridine-type Bidentate Auxiliary
作者:Rikuo Kajiwara、Koji Hirano、Masahiro Miura
DOI:10.1246/cl.210439
日期:2021.10.5
A Cu-mediated ortho-selective C–H cyanation of phenols with ethyl cyanoformate as the cyano source has been developed. The key to success is the introduction of 4,4′-di-tert-butyl-2,2′-bipyridine (dtbpy) bidentate auxiliary on the phenol oxygen, which is easily attachable, detachable, and recyclable. The newly developed protocol is tolerant of several carbonyl functional groups, which are incompatible with previous Lewis-acid-promoted cyanation of phenols.
一种以乙基氰基甲酸酯为氰源的酚类化合物铜催化的邻位选择性C-H氰化反应已经开发出来。成功的关键在于在酚羟基上引入4,4′-二叔丁基-2,2′-联吡啶(dtbpy)双齿辅助配体,这种配体易于附着、脱离和循环使用。新开发的反应方案对多种羰基官能团具有耐受性,而这些官能团在先前的路易斯酸促进的酚类氰化反应中是不相容的。