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 N-aryl indazol-3-ols, which provides the succinimide-bearing
indazol-3-ol 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 fluorescence-probe-linked maleimides.