Metal-free synthesis of 2,2-disubstituted indolin-3-ones

A straightforward method for the synthesis of indolin-3-ones bearing a C2-quaternary functionality is reported. A series of 2,2-disubstituted indolin-3-ones were constructed in up to 94% yields in the absence of a metal catalyst. This cross-coupling reaction allows the facile synthesis of 2,2-disubstituted indolin-3-ones from readily available substrates in a short reaction time.