A Phosphetane Catalyzes Deoxygenative Condensation of α-Keto Esters and Carboxylic Acids via P<sup>III</sup>/P<sup>V</sup>═O Redox Cycling
作者:Wei Zhao、Patrick K. Yan、Alexander T. Radosevich
DOI:10.1021/ja511889y
日期:2015.1.21
A small-ring phosphacycle is found to catalyze the deoxygenative condensation of α-keto esters and carboxylic acids. The reaction provides a chemoselective catalytic synthesis of α-acyloxy ester products with good functional group compatibility. Based on both stoichiometric and catalytic mechanistic experiments, the reaction is proposed to proceed via catalytic P(III)/P(V)═O cycling. The importance
Intermolecular Reductive C–N Cross Coupling of Nitroarenes and Boronic Acids by P<sup>III</sup>/P<sup>V</sup>═O Catalysis
作者:Trevor V. Nykaza、Julian C. Cooper、Gen Li、Nolwenn Mahieu、Antonio Ramirez、Michael R. Luzung、Alexander T. Radosevich
DOI:10.1021/jacs.8b10769
日期:2018.11.14
intermolecular C-N coupling is reported. The method employs a small-ring organophosphorus-based catalyst (1,2,2,3,4,4-hexamethylphosphetane) and a terminal hydrosilane reductant (phenylsilane) to drive reductive intermolecular coupling of nitro(hetero)arenes with boronic acids. Applications to the construction of both Csp2-N (from arylboronic acids) and Csp3-N bonds (from alkylboronicacids) are demonstrated;
Poly(methylhydrosiloxane) as a reductant in the catalytic base-free Wittig reaction
作者:Jan Tönjes、Lars Longwitz、Thomas Werner
DOI:10.1039/d1gc00953b
日期:——
catalytic, base-free Wittigreaction forming highly functionalized alkenes with PMHS as a terminal reductant and butylacetate as a green solvent. Poly(methylhydrosiloxane) (PMHS) is a non-toxic, enviromentally friendly, inexpensive and easy to handle reductant. However, the inherent low reactivity hampers its applicability in catalytic reactions, such as P(III)/P(V) redox cycling reactions. Most of these
Coordination chemistry of cis,cis and trans,trans 1,1′-[1,2-phenylenebis(methylene)]bis(2,2,3,4,4-pentamethylphosphetane)
作者:Dennis Coleman、Peter G. Edwards、Benson M. Kariuki、Paul D. Newman
DOI:10.1039/b924982f
日期:——
The cis,cis (5) and trans,trans (9) forms of the bidentate ligand 1,1′-[1,2-phenylenebis(methylene)]bis(2,2,3,4,4-pentamethylphosphetane) have been prepared from common precursors using two separate synthetic routes. The cis,cisisomer is attained selectively through the direct reaction of two mol equivalents of 2,2,3,4,4-pentamethylphosphetane with α,α′-dibromo-o-xylene in acetone. Protection of the
A Biphilic Phosphetane Catalyzes N–N Bond-Forming Cadogan Heterocyclization via P<sup>III</sup>/P<sup>V</sup>═O Redox Cycling
作者:Trevor V. Nykaza、Tyler S. Harrison、Avipsa Ghosh、Rachel A. Putnik、Alexander T. Radosevich
DOI:10.1021/jacs.7b03260
日期:2017.5.24
chemoselective catalytic synthesis of 2H-indazoles, 2H-benzotriazoles, and related fused heterocyclic systems with good functional group compatibility. On the basis of both stoichiometric and catalytic mechanistic experiments, the reaction is proposed to proceed via catalytic PIII/PV═O cycling, where DFT modeling suggests a turnover-limiting (3+1) cheletropic addition between the phosphetane catalyst and nitroarene