Controlled Anion Migrations with a Mixed Metal Li/K-TMP Amide: General Application to Benzylic Metalations
作者:Patricia Fleming、Donal F. O’Shea
DOI:10.1021/ja110234v
日期:2011.2.16
A general method is described for benzylic metalation of o-, m-, and p-substituted toluenes using a mixed metal amide base generated from BuLi/KOtBu/TMP at -78 degrees C in THF. The excellent selectivity achieved can be rationalized by the ability of the mixed metal amide base to facilitate an anion migration from the kinetic (o-aryl) to the benzylic metalation site. Remarkably, this controlled anion migration is achievable with catalytic amounts of TMP at -78 degrees C.