Abstract
The first published synthesis of unprotected carboxy indazoles from the corresponding bromoindazoles is described. This is achieved via Pd(II)-catalyzed carbonylation and is demonstrated to work on a variety of indazoles.
GRAPHICAL ABSTRACT
ACKNOWLEDGMENT
We gratefully acknowledge the help of Gemma Chew in compiling this paper.
Notes
Note. Conditions: PdCl2, BINAP, CO (40 bar), Et3N, MeOH/CH3CN.
a Yields refer to isolated products.
Note. Conditions: Pd(dppf)Cl2, CO (3 bar), NaOAc, MeOH/DMF.
a Yields refer to isolated products.