Lithium (α-methylbenzyl)allylamide: a differentially protected chiral ammonia equivalent for the asymmetric synthesis of β-amino acids and β-lactams
作者:Stephen G. Davies、David R. Fenwick
DOI:10.1039/c39950001109
日期:——
The addition products from the highly stereoselective conjugateadditions of lithium (αS)-(α-methylbenzyl)allylamide to α, β-unsaturated tert-butyl esters are efficiently deallylated with tris(triphenylphosphine)rhodium(I) chloride and converted, after transesterification to the methyl esters and cyclisation with methylmagnesiumbromide, to the corresponding homochiral N-(α-methylbenzyl)-4-substituted-azetidm-2-ones
Asymmetric synthesis of homochiral Baylis–Hillman products employing (R)-N-methyl-N-α-methylbenzyl amide
作者:Stephen G Davies、Christian A.P Smethurst、Andrew D Smith、G.Darren Smyth
DOI:10.1016/s0957-4166(00)00224-x
日期:2000.6
The conjugate addition of (R)-N-methyl-N-alpha-methylbenzyl amide to tert-butyl cinnamate followed by an asymmetric aldol reaction and subsequent N-oxidation/Cope elimination affords beta-substituted homochiral Baylis-Hillman products in good yield. (C) 2000 Elsevier Science Ltd. All rights reserved.