Synthesis of aryl phosphinates was achieved through cross-coupling reactions of aryl iodides with H-phosphinates catalyzed by nickel under mild conditions. The method was applicable to various aryl iodides and H-phosphinates having defined stereochemistry at the phosphorus atom.
Both enantiomers of 1,1-diethoxyethyl(aminomethyl)phosphinates were prepared through chromatographic separation of a diastereomeric mixture derived from (S)-phenylethylamine and 1,1-diethoxyethyl-H-phosphinate. The individual enantiomer was transformed into α-substituted α-amino-H-phosphinate with high enantiomeric purity by a highly diastereoselective alkylation at the α-carbon on the basis of our
Synthesis of α-amino-α′-hydroxyphosphinates has been achieved through hydrophosphinylation of α-amino-H-phosphinates to aldehydes with highly retentive phosphorus chirality. Treatment of α-substituted α-amino-H-phosphinates with aldehydes in the presence of magnesium oxide without solvent gave α-amino-α′-hydroxyphosphinates. The reaction proceeded with 80-94 % retention of configuration at the phosphorus atom.
Diastereoselective addition of alpha-substituted alpha-amino-H-phosphinates to imines is described. Among Lewis acids, Yb(OTf)(3) was found to be the best catalyst. alpha,alpha'-Diaminophosphinic derivatives were obtained with de's ranging from 10 to 95% in the presence of Yb(OTf)(3) as an efficient Lewis acid catalyst. The reaction proceeded with retention of configuration at the phosphorus atom. (c) 2007 Elsevier Ltd. All rights reserved.
Diastereoselective alkylation of iminomethylenephosphinates possessing an asymmetric center at the phosphorus atom
Diastereoselective synthesis of alpha-aminophosphinates was achieved by alkylation of imines with a 1,1-diethoxyethylphosphinyl group. These products were readily converted into alpha-amino-H-phosphinates. (c) 2006 Elsevier Ltd. All rights reserved.