Merging 'Anti-Baldwin' 3-Exo-Dig Cyclization with 1,2-Alkynyl Migration for Radical Alkylalkynylation of Unactivated Olefins

摘要

A new combination of "anti-Baldwin" 3-exo-dig cyclization with 1,2-alkynyl migration of 1,4-enynes with simple cycloalkanes was established, enabling C-C breaking and reconstruction to access a wide range of alpha-alkynyl ketones with generally good yields by FeCl2/ditert-butyl peroxide (DTBP) as a catalytic oxidation system. Radical induced C(sp(3))-H functionalization of cycloalkanes was realized, leading to the direct formation of C(sp(3))-C(sp(3)) and C(sp)-C(sp(3)) bonds. The mechanism for forming alpha-alkynyl ketones was proposed.