A Reagent-Controlled Phospha-Michael Addition Reaction of Nitroalkenes with Bifunctional N-Heterocyclic Phosphine (NHP)-Thioureas
Bifunctional N-heterocyclic phosphine (NHP)-thioureas have been successfully applied for phospha-Michael addition reaction of nitroalkenes to afford diversely substituted β-nitrodiazaphosphonates. This transformation takes place at room temperature under catalyst-free conditions and exhibits broad functional group tolerance. The key to success in catalyst, additive-free reaction conditions is the suitable hydrogen-bond activation of the nitro group by a Brønsted acid (thiourea), which artfully combined with the highly nucleophilic NHP motif for a synergetic effect. Importantly, this transformation enables a two-step synthesis of pharmaceutically, biologically significant β-amino phosphonic acids. © 2016 American Chemical Society.
Kang, J. Y.
A Reagent-Controlled Phospha-Michael Addition Reaction of Nitroalkenes with Bifunctional N-Heterocyclic Phosphine (NHP)-Thioureas.
Journal of Organic Chemistry, 81(23),