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(C 6 F 5 ) 3 , Rh 2 (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.