An Improved Method for the Bromination of Metalated Haloarenes via Lithium, Zinc Transmetalation: A Convenient Synthesis of 1,2-Dibromoarenes
作者:Karsten Menzel、Ethan L. Fisher、Lisa DiMichele、Doug E. Frantz、Todd D. Nelson、Michael H. Kress
DOI:10.1021/jo052515k
日期:2006.3.1
A facile protocol for the synthesis of 1,2-dibromoarenes is described. A standard ortho-lithiation/bromination procedure, when applied to bromoarenes, resulted in poor yields of the corresponding 1,2-dibromoarenes (13−62% yield). However, transmetalation of the transient aryllithium intermediate to an arylzinc species with ZnCl2, followed by bromination, resulted in dramatically improved yields of
描述了一种用于合成1,2-二溴芳烃的简便方案。如果将标准的邻位锂化/溴化工艺应用于溴代芳烃,则会导致相应的1,2-二溴芳烃的收率不佳(13-62%的收率)。但是,将过渡性芳基锂中间体用ZnCl 2过渡成芳基锌物种,然后进行溴化,可显着提高合成上有用的1,2-二溴芳烃的收率(68-95%的收率)。