reaction of phosphazenes and fluorinated acetylenic phosphonates. Subsequent reduction of both carbon–carbon and carbon–nitrogen double bonds of these 1-azadienes I affords the fluorine-containing β-aminophosphonates II, with the syn β-aminophosphonate being obtained as the major diastereoisomer. Base-mediated cyclocondensation of a diastereomeric mixture of aminophosphonates II leads exclusively to a new
derived from α-aminoesters is achieved through an aza-Wittig reaction of phosphazenes with β,γ-unsaturated α-ketoesters. Regioselective 1,2-reduction of these functionalized 1-azadienes affords vinylglycine derivatives, while conjugative 1,4-reduction gives α-dehydroamino acid compounds. Reduction of both the carbon−carbon and the imine−carbon−nitrogen double bonds leads to the formation of α-amino acid
[GRAPHIC]An efficient synthesis of alpha,beta-unsaturated imines derived from alpha-aminophosphonates is achieved through aza-Wittig reaction of P-trimethyl phosphazenes with beta,gamma-unsaturated alpha-ketophosphonates. Selective 1,2-reduction of such 1-azadienes affords beta,gamma-unsaturated alpha-aminophosphonates, phosphorylated analogs of vinylglycines, which are hydrogenated to yield saturated alpha-aminophosphonate derivatives.
α-Ketiminophosphonates: Synthesis and Applications
Electronic Structures and Reactivity Profiles of Aryl Nitrenoid-Bridged Dicopper Complexes
作者:Kurtis M. Carsch、James T. Lukens、Ida M. DiMucci、Diana A. Iovan、Shao-Liang Zheng、Kyle M. Lancaster、Theodore A. Betley
DOI:10.1021/jacs.9b09616
日期:2020.2.5
indicate that the formally Class IIIA mixed valence complexes of the type [(Rdmx)Cu2(µ2-NAr)]-, featuring significant NAr-localized spin following reduction from electronic population of the [Cu2(µ2-NAr)] π* manifold and contrasting previ-ous methods for engendering iminyl character through chemical oxidation. The reactivity of the isolable imido and iminyl complexes are examined for prototypical radical-promoted