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

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.