Catalyst-dependent chemoselective insertion of diazoalkanes into the N–H/C–H/O–H/C–O bonds of 2-hydroxybenzothiazoles

Abstract

The control of chemoselective insertions of diazoalkanes into 2-hydroxybenzothiazoles is challenging. Herein, the chemoselective N–H, O–H, C–O or C–H bond insertions of diazoalkanes into 2-hydroxybenzothiazoles are achieved using B(C₆F₅)₃, Rh₂(OAc)₄ or TfOH as the catalyst. This affords routes to 54 benzothiazole derivatives. These protocols are scalable and demonstrate the complementary nature of Lewis acid, transition metal and Brønsted acid catalyses.