Bu4NI-Catalyzed and tBuOOH-Oxidized Esterification of Aldehydes with Alkyl Halides in Water

摘要

The importance of esters has stimulated significant efforts to develop efficient methods for their synthesis. In this study, an oxidative esterification of aldehydes with alkyl halides by using tert-butyl hydroperoxide as an oxidant, Bu4NI as catalyst, and water as solvent is presented. Notably, this novel esterification protocol is suitable for both aromatic and aliphatic aldehydes, primary and secondary alkyl halides to give ester products with broad structural diversity. Through an intramolecular version of this novel esterification process, an alternative synthetic approach toward the biologically interesting isobenzofuran-1(3H)-one was also realized. Compared with literature procedures, the synthetic strategies developed herein showed advantages such as direct use of commercially available and economical starting materials, wide substrate scope, good tolerance of functional groups, sustainable oxidant, and no need of an inert atmosphere or dry solvents.