Simple unprecedented conversion of phosphine oxides and sulfides to phosphine boranes using sodium borohydride
作者:Kamalraj V. Rajendran、Declan G. Gilheany
DOI:10.1039/c1cc14856g
日期:——
A variety of phosphineoxides and sulfides can be efficiently converted directly to the correspondingphosphine boranes using oxalyl chloride followed by sodium borohydride. Opticallyactive P-stereogenic phosphineoxides can be converted stereospecifically to phosphine boranes with inversion of configuration by treatment with Meerwein's salt followed by sodium borohydride.
A U-Turn in the Asymmetric Appel Reaction: Stereospecific Reduction of Diastereomerically Enriched Alkoxyphosphonium Salts Allows the Asymmetric Synthesis of P-Stereogenic Phosphanes and Phosphane Boranes
作者:Kamalraj V. Rajendran、Jaya S. Kudavalli、Katherine S. Dunne、Declan G. Gilheany
DOI:10.1002/ejoc.201200285
日期:2012.5
recovered unchanged. The simple and efficient protocol significantly expands the scope of our asymmetric Appel process. The crucial step in the preparation involves stereospecificreduction of intermediate diastereomeric alkoxyphosphonium salts, which are obtained in the reaction of phosphane, hexachloroacetone, and menthol. Thereby, reaction with LiAlH4 or NaBH4 gives the corresponding phosphanes or phosphane
Identification of a key intermediate in the asymmetric Appel process: one pot stereoselective synthesis of P-stereogenic phosphines and phosphine boranes from racemic phosphine oxides
作者:Kamalraj V. Rajendran、Declan G. Gilheany
DOI:10.1039/c2cc34136k
日期:——
racemic phosphine oxides with oxalyl chloride and chiral non-racemic alcohol generates the same ratios of diastereomeric alkoxyphosphonium salts obtained in the corresponding asymmetric Appel process, strongly implicating the intermediate chlorophosphonium salt in the stereoselecting step. Subsequent reduction allows a novel synthesis of enantioenriched P-stereogenic phosphines-phosphine boranes.
Lithium Borohydride for Achiral and Stereospecific Reductive Boronation at Phosphorus: Lack of Electronic Effects on Stereoselective Formation of Alkoxyphosphonium Salts
作者:Sulaiman S. Al Sulaimi、Kamalraj V. Rajendran、Declan G. Gilheany
DOI:10.1002/ejoc.201500521
日期:2015.9
as a preferred, simple and effective reagent for reductive boronation of achiral and racemic chlorophosphonium salts (CPS) and for diastereomeric alkoxyphosphonium salts (DAPS), both of which are, in turn, easily generated from either the corresponding phosphane or, more conveniently, the phosphane oxide. Further, we have shown that the DAPS reduction/boronation could be achieved with complete stereocontrol
Hammond Postulate Mirroring Enables Enantiomeric Enrichment of Phosphorus Compounds via Two Thermodynamically Interconnected Sequential Stereoselective Processes
作者:Kamalraj V. Rajendran、Kirill V. Nikitin、Declan G. Gilheany
DOI:10.1021/jacs.5b04415
日期:2015.7.29
unreacted enriched DAPS with lithium tri-sec-butylborohydride (commercially distributed as L-Selectride reagent) at different time intervals after the start of reaction, which gives progressively higher ee of the phosphine product with time. It is proposed that the Hammond postulate operates for both formation and decomposition of DAPS intermediate so that the lower rate of formation and faster subsequent