The mechanism behind enhanced reactivity of unsaturated phosphorus(<scp>v</scp>) electrophiles towards thiols
Y.H. Park, Alice Baumann, Hye‐Jin Moon, Stephen A. Byrne, Marc‐André Kasper, Songhwan Hwang, Han Sun, Mu‐Hyun Baik, Christian P. R. Hackenberger
Abstract
-selectivity for thiol additions to ethynyl derivatives, were further elucidated using DFT calculations. Hyperconjugation was a key means of stabilizing the intermediate generated upon the thiol addition, thus determining both the reactivity and stereoselectivity of unsaturated P(v) electrophiles. Specifically, the energetically low-lying σ antibonding orbital of the P-S bond more readily stabilizes the electron density from the lone pair (LP) of the generated carbanion, rendering the phosphonothiolates more reactive compared to the derivatives bearing oxygen and nitrogen. Our studies provide a detailed mechanistic picture for designing P(v)-based electrophiles with fine-tuned reactivity profiles.