Stereoselective Addition of Grignard Reagents to New P-Chirogenic N-Phosphinoylbenzaldimines: Effect of the Phosphorus Substituents on the Stereoselectivity
give both diastereoisomers in high yields and with promising diastereomeric ratios. Then N-[(tert-butyl)(phenyl)phosphinoyl]benzaldimine, which displayed the best results, was subjected to the 1,2-addition of various Grignardreagents to evaluate the best chiral induction due to the stereogenic phosphorus atom. The corresponding adducts were obtained in excellent yields and with moderate to excellent diastereoisomeric
Diastereoselective alkynylation of chiral phosphinoylimines: preparation of optically active propargylamines
作者:Mounira Benamer、Serge Turcaud、Jacques Royer
DOI:10.1016/j.tetlet.2009.11.091
日期:2010.1
Chiral phosphinoylimines were prepared from methylphenylphosphonamides and tested as new chiral and activated imines. The addition of aluminum acetylides was proved to be highly diastereoselective while lithium or magnesium acetylides gave poor results. The cleavage of the chiral auxiliary was done under mild conditions and allows the recovery of the starting phosphonamide without loss of optical purity