Synthesis of indoles using (N‐arylaminomethyl)diphenylphosphine oxides

Abstract A new route for the synthesis of 1,3‐disubstituted indoles, based on (N‐arylaminomethyl)‐diphenylphosphine oxide (1) chemistry, is described. Adducts 2, obtained by addition of the carbanions from 1 to aldehydes, were treated with p‐toluenesulfonic acid to form the desired indoles 4 in good yields, without isolation of the intermediate amino ketones 3.