Tuning of Copper-Catalyzed Multicomponent Reactions toward 3-Functionalized Oxindoles.

A tunable copper-catalyzed azide-alkyne cycloaddition (CuAAC)-initiated multicomponent reaction strategy for the construction of 3-functionalized indolin-2-ones is reported. Upon controlling the ring opening of four-membered O-heterocyclic intermediates, this unique method enables the divergent derivatization of N-protected isatins to give three-component (3-CR) and four-component (4-CR) adducts, respectively.e [ABSTRACT FROM AUTHOR]