Silver(I) oxide - /DBU - promoted synthesis of dihydrofuran units through allenyl silver formation

Chemistry A European Journal

DOI: 10.1002/chem.202002696

A formal [3+2] cyclization mediated by silver(I) oxide and DBU is described herein. Through a broad variety of carbonyl compounds, this system can promote cyclization reactions with high yield (up to 85%) and diastereoselectivity (up to 95:5) for a straightforward access to complex and congested dihydrofuran derivatives in one step using smooth conditions. Based on DFT studies, the proposed mechanism would involve an allenyl silver intermediate.