Diverse Reactions of Vinyl Diazo Compounds with Quinone Oxonium Ions, Quinone Imine Ketals, and Eschenmoser’s Salt
Haifeng Zheng, Kan Wang, Isa Faghihi, Wendell P. Griffith, Hadi D. Arman, Michael P. Doyle
Abstract
Metal-free electrophile addition to vinyl diazo compounds reveals highly selective formal [3 + 2] cyclization, 1,2-difunctionalization of alkenes, and C–H functionalization. The success of these methodologies is based on electrophilic addition to the vinylogous position of vinyl diazo compounds, forming vinyl diazonium ion intermediates. By using diverse electrophilic reagents, these highly reactive intermediates show diverse reactivities, affording β-benzohydrofuran-, β-methoxy-β-benzyl-, and γ-aminoallyl-substituted α-diazo esters in high yields and selectivities. Further transformations that include migration, oxidation, ring-expansion, and conjugate addition highlight the potential utility of this method.