Phosphine-mediated formal [5 + 1] aminobenzannulations of Morita–Baylis–Hillman carbonates with isocyanates

Abstract

Morita–Baylis–Hillman (MBH) carbonates have been widely used in many meaningful annulations. Herein we report the use of an MBH-carbonate-derived relatively long-chained, C5, synthon to enable a formal [5 + 1] annulation with readily available isocyanates. The reaction proceeds via a tandem Wittig and aminobenzannulation process, smoothly constructing both diarylamines and anilines with a broad scope of substrates and excellent chemoselectively.