Dirhodium carboxylate catalysts from 2-fenchyloxy or 2-menthyloxy arylacetic acids: enantioselective C-H insertion, aromatic addition and oxonium ylide formation/rearrangement

Abstract

A new class of dirhodium carboxylate catalysts have been designed and synthesized from 2-fenchyloxy or 2-menthyloxy arylacetic acids which display excellent enantioselectivity across a range of transformations of alpha-diazocarbonyl compounds. The catalysts were successfully applied to enantioselective C-H insertion reactions of aryldiazoacetates and alpha-diazo-beta-oxosulfones affording the respective products in up to 93 % ee with excellent trans diastereoselectivity in most cases. Furthermore, efficient desymmetrization in an intramolecular C-H insertion was achieved. In addition, these catalysts prove highly enantioselective for intramolecular aromatic addition with up to 88% ee, and oxonium ylide formation and rearrangement with up to 74% ee.