Rh(iii)-Catalyzed and synergistic dual directing group-enabled redox-neutral [3+3] annulation of N-phenoxyacetamides with α-allenols

Abstract

By virtue of α-allenols as innovative three-carbon annulation components, the Rh(III)-catalyzed redox-neutral C–H coupling of N-phenoxyacetamides with α-allenols has been realized for the assembly of 4-alkylidene chroman-2-ol frameworks via an unusual [3+3] annulation. This transformation features good functional group tolerance, specific regio-/chemoselectivity and potential synthetic utility. Mechanistic studies reveal that synergistic coordination modes between the dual directing groups (–ONHAc and –OH) and the rhodium metal center account for the observed exclusive selectivity.