Et3B- and Et2Zn-Mediated Radical Additions to Glyoxylate Imines, Compared Stereoinductions
摘要:
1,3-Stereoinduction in the addition of alkyl radicals to glyoxylic imines derived from various chiral amines has been investigated. New synthetic methodologies involving Et3B and Et2Zn as mediators have been compared. Dihydro-1,4-oxazin-2-one (2b) gave the highest d.e. but no chemoselectivity. Open chain analogues derived from beta-alkoxyamines led to good stereoinduction when the reaction was performed with Et2Zn which is a bidentate complexing reagent. (C) 2000 Elsevier Science Ltd. All rights reserved.
1,3-Stereoinduction in Radical Additions to Glyoxylate Imines
作者:Michèle P. Bertrand、Laurence Feray、Robert Nouguier、Lucien Stella
DOI:10.1055/s-1998-1763
日期:1998.7
Addition of alkyl radicals to the acyclic glyoxylate imine 1 proceeded with a 70 : 30 stereoinduction, even at -78 °C. Addition to the cyclic imine 4b resulted in complete stereocontrol at -40 °C.
Et3B- and Et2Zn-Mediated Radical Additions to Glyoxylate Imines, Compared Stereoinductions
作者:Michèle P. Bertrand、Stéphanie Coantic、Laurence Feray、Robert Nouguier、Patricia Perfetti
DOI:10.1016/s0040-4020(00)00327-6
日期:2000.6
1,3-Stereoinduction in the addition of alkyl radicals to glyoxylic imines derived from various chiral amines has been investigated. New synthetic methodologies involving Et3B and Et2Zn as mediators have been compared. Dihydro-1,4-oxazin-2-one (2b) gave the highest d.e. but no chemoselectivity. Open chain analogues derived from beta-alkoxyamines led to good stereoinduction when the reaction was performed with Et2Zn which is a bidentate complexing reagent. (C) 2000 Elsevier Science Ltd. All rights reserved.