One-pot synthesis of substituted quinolines and 3,3′-(arylmethylene)bis(1H-indoles) via a metal-free polyphosphoric acid-mediated acetylene hydrolysis strategy

Abstract

Simple one-pot methods for the synthesis of polysubstituted quinolines and 3,3 ′-(arylmethylene) bis (1H-indoles) have been developed using a polyphosphoric acid-mediated alkynes hydrolysis strategy. Sequential addition of substituted alkynes to an o-nitro(o-aminophenyl)carbonyl compound under solvent-free conditions followed by cyclization in polyphosphoric acid afforded 15 diverse quinolines in good to excellent yields. Furthermore, a three-component reaction between aldehydes, acetylenes, and arylhydrazines provided a simple and rapid method for the synthesis of 3,3′-(arylmethylene)bis(1H-indoles) from readily available reagents