CS 2 Induced Annulation of 2‐Alkynyl Nitroarenes With Indoles: Construction of 2,2‐Disubstituted Indolin‐3‐ones

An efficient CS 2 induced annulation of 2‐alkynyl nitroarenes with indoles for the construction of 2,2‐disubstituted indolin‐3‐ones has been developed. A range of functionalized indolin‐3‐ones were prepared in moderate to good yields from easily available starting materials. This reaction directly synthesizes 2,2‐disubstituted indol‐3‐ones from ortho ‐alkynyl nitroarenes in a single step. This protocol avoids the need for preformed isatogen intermediates that require noble transition metal catalysis in prior methods.