Phosphorus(III)-Mediated Stereoconvergent Formal [4+1]-Cycloannulation of 1,2-Dicarbonyls and o-Quinone Methides: A Multicomponent Assembly of 2,3-Dihydrobenzofurans.
A phosphorus(III)-mediated formal [4+1]-cycloaddition of 1,2-dicarbonyls and o-quinone methides to provide 2,3-dihydrobenzofurans is described. By exploiting the carbene-like nature of dioxyphospholenes, dihydrobenzofurans bearing a quaternary center at C2 are obtained in 30-92% yield with diastereoselectivities up to ≥20:1. This study highlights the subtle steric interactions involved in the [4+1]-cycloannulation and the impact they have on yield and stereoselectivity in dihydrobenzofuran formation.
Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Kevin X
KX
Rodriguez
Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Justin D
JD
Vail
Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Brandon L
BL
Ashfeld