Synthesis of Succinimide-Linked Indazol-3-ols Derived from Maleimides under Rh(III) Catalysis

The structural modification of N-aryl indazolols as tautomers of N-aryl indazolones has been established as a hot topic in pharmaceutics and medicinal chemistry. We herein disclose the rhodium(III)-catalyzed 1,4-addition reaction of maleimides with Naryl indazol-3-ols, which provides the succinimide-bearing indazol-3ol scaffolds with complete regioselectivity and a good functional group tolerance. Notably, the versatility of this protocol is demonstrated by the use of drug-molecule-linked and fluorescenceprobe-linked maleimides.