Synthesis of <i>P</i>-Stereogenic Compounds via Kinetic Deprotonation and Dynamic Thermodynamic Resolution of Phosphine Sulfides: Opposite Sense of Induction Using (−)-Sparteine
作者:Jonathan J. Gammon、Viktoria H. Gessner、Greg R. Barker、Johan Granander、Adrian C. Whitwood、Carsten Strohmann、Peter O’Brien、Brian Kelly
DOI:10.1021/ja1060966
日期:2010.10.6
at a lithiated carbon atom. The major, thermodynamically preferred diastereomeric (-)-sparteine-complexed lithated phosphine sulfide was investigated by X-ray crystallography and computational methods at the B3LYP/6-31+G(d) level. Through the interconversion of the R(P) and S(P) stereoisomers of the lithiated methylphosphine sulfide, a novel dynamic thermodynamicresolution of a racemic lithiated phosphine
Mechanism of biphosphine disulphide formation in reactions of thiophosphoryl and phosphonothioic halides with Grignard reagents
作者:P. C. Crofts、I. S. Fox
DOI:10.1039/j29680001416
日期:——
The factors favouring formation of biphosphine disulphides are identified and evidence is presented (a) for attack by the Grignardreagent on chlorine, and (b) that phosphorus–phosphorus bond formation does not occur when two organic groups are attached to phosphorus. A mechanism is proposed, involving simultaneous removal of two halogen atoms from the thiophosphorus halide yielding a phosphinidene
Regioselective Lithiation of Silyl Phosphine Sulfides: Asymmetric Synthesis of <i>P</i>-Stereogenic Compounds
作者:Jonathan J. Gammon、Peter O’Brien、Brian Kelly
DOI:10.1021/ol901977p
日期:2009.11.5
lithiation of a dimethylphosphine sulfide), a two-step process of regioselective lithiation-trapping and silyl group removal has been used to prepare a range of P-stereogenic compounds, including precursors to diphosphine ligands (e.g., Mini-PHOS). This two-step protocol delivers products with the opposite configuration to that obtained by direct asymmetric lithiation−trapping of a dimethylphosphine sulfide