Tandem addition of phosphite nucleophiles across unsaturated nitrogen-containing systems: mechanistic insights on regioselectivity

W. Debrouwer, D. Hertsen, T.S.A Heugebaert, E. Birsen Boydas, V. Van Speybroeck, S. Catak, C.V. Stevens
Journal of Organic Chemistry
82 (1), 188–201


The addition of phosphite nucleophiles across linear unsaturated imines is a powerful and atom-economical methodology for the synthesis of aminophosphonates. These products are of interest from both a biological and a synthetic point of view: they act as amino acid transition state analogs and Horner–Wadsworth–Emmons reagents, respectively. In this work the reaction between dialkyl trimethylsilyl phosphites and α,β,γ,δ-diunsaturated imines was evaluated as a continuation of our previous efforts in the field. As such, the first conjugate 1,6-addition of a phosphite nucleophile across a linear unsaturated N-containing system is reported herein. Theoretical calculations were performed to rationalize the observed regioselectivites and to shed light on the proposed mechanism.