A novel 1,3,2-diazaphospholidine (N-heterocyclic phosphine)-thiourea-mediated phospha-Mannich/intramolecular nucleophilic substitution reaction has been developed for the construction of an N-C-P bond unit. This transformation enabled a rapid access to cyclic tertiary α-amino phosphonates in one-pot procedure under additive-free mild reaction conditions. This study revealed the critical role of thiourea moiety of the N-heterocyclic phosphine-thiourea in the sequential intramolecular nucleophilic substitution reaction of the phosphonylation.

An efficient and practical protocol for completely regioselective and highly stereoselective synthesis of vinyldiazaphosphonates from N-heterocyclic phosphine (NHP) and allenes via phospha-Michael/intramolecular nucleophilic substitution reaction has been developed. This transformation enabled the synthesis of valuable densely functionalized vinyldiazaphosphonates with a β-, γ-unsaturated ester moiety under mild reaction conditions. Synthetic utility of vinyldiazaphosphonates was demonstrated by a series of synthetic manipulations.

For the construction of an N—C—P bond unit, a 1,3,2‐diazaphospholidine (N‐heterocyclic phosphine)—thiourea‐mediated phospha‐Mannich/intramolecular nucleophilic substitution reaction is developed.

Utility of Bifunctional N-Heterocyclic Phosphine (NHP)-Thioureas for Metal-Free Carbon-Phosphorus Bond Construction Toward Regio-and StereoselectiveFormation of Vinylphosphonates. -This novel N-heterocyclic phosphine--promoted phospha-Michael/intramolecular nucleophilic substitution reaction allows for the stereoselective construction of vinyldiazaphosphonates in moderate to excellent yields. The Michael addition of the NHP to -substituted or -substituted allenes proceeds with complete regioselectivity and reveals good tolerance of various electron--withdrawing groups on the allenes. This protocol represents the first general application of bifunctional NHPs in organic synthesis to facilitate the rapid C-P bond forming approach to vinylphosphonate compounds and is a complement to classical methods like metal-promoted synthesis of vinylphosphonates. -(MULLA, K.; ALESHIRE, K. L.; FORSTER, P. M.; KANG*, J. Y.; J. Org. Chem. 81 (2016) 1, 77-88, http://dx.doi.org/10.1021/acs.joc.5b02184 ; Dep. Chem. Biochem., Univ. Nev., Las Vegas, NV 89154, USA; Eng.) -H. Hoennerscheid