Addressing the Configuration Stability of Lithiated Secondary Benzylic Carbamates for the Development of a Noncryogenic Stereospecific Boronate Rearrangement

Abstract

A practical noncryogenic process for the Aggarwal stereospecific boronate rearrangement with chiral secondary benzylic carbamates has been developed. The use of LDA instead of <i>sec</i>-BuLi combined with an <i>in situ</i> trapping of the unstable lithiated carbamate was critical to success. Furthermore, this new process increased the substrate scope to include the versatile aryl iodide and bromide substrates. The methodology was applied to a diverse array of substrates and was demonstrated on multikilogram scale