Rh(II)-Catalyzed Denitrogenative Reaction of N‑Sulfonyl-1,2,3-triazoles with Isatins for the Construction of Indigoids

A convenient, Rh­(II)-catalyzed, denitrogenative reaction of N-sulfonyl-1,2,3-triazoles and isatins to access (E)-2-(1-amino-2-oxo-2-phenyl­ethylidene)­indolin-3-ones, the core structure of indigo dyes, was achieved under operationally simple conditions with high levels of diastereoselectivity. Moreover, photophysical and electrochemical studies were conducted to understand their applicability in optoelectronic applications.