Metal-Free Electrophilic Phosphination/Cyclization of Alkynes

摘要

A metal-free electrophilic phosphination reaction has been developed. Electrophilic phosphorus species generated in situ from secondary phosphine oxides and Tf_2O smoothly couple with alkynes possessing pendant nucleophiles to afford the corresponding phos-phinated cyclization products in good yield. Preliminary NMR studies show that phosphirenium species may be involved as intermediates of the cyclization reactions.