Synthesis of unsymmetrical diaryl oxindoles/isoquinolinediones using 2-phenoxy-1H-benzo[d]imidazole as an integrated diarylating reagent

Abstract

Presented herein is a novel synthesis of unsymmetrical 3,3-diaryl oxindoles and 4,4-diaryl isoquinolinediones through the cascade reactions of 2-phenoxy-1H-benzo[d]imidazoles with diazo oxindoles or diazo homophthalimides. To accomplish the challenging unsymmetrical diarylation, 2-phenoxy-1H-benzo[d] imidazole acts as not only a substrate for C–H bond functionalization but also an unprecedented integrated diarylating reagent to provide both benzimidazolyl and 2-hydroxyphenyl units through C–H/C–O bond cleavage. In general, this developed protocol has advantages such as easily obtainable starting materials, valuable products, a unique reaction pathway, concise synthetic procedures, good compatibility with diverse functional groups, suitability for gram-scale application and late-stage functionalization of drug molecules.