Doubly diastereoselective conjugate addition of enantiopure lithium amides to enantiopure N-enoyl oxazolidin-2-ones: a mechanistic probe
作者:Stephen G. Davies、Ai M. Fletcher、Gesine J. Hermann、Giovanna Poce、Paul M. Roberts、Andrew D. Smith、Miles J. Sweet、James E. Thomson
DOI:10.1016/j.tetasy.2010.03.033
日期:2010.7
diastereoselective conjugateaddition of the antipodes of lithium N-benzyl-N-(α-methylbenzyl)amide to a range of enantiopure N-enoyl oxazolidin-2-ones has been used as a mechanistic probe to determine that the reactive conformation is the anti-s-cis form. The β-amino carbonyl products resulting from these conjugateaddition reactions are useful templates for further elaboration into an α,β,α-pseudotripeptide
Asymmetric three- and [2 + 1]-component conjugate addition reactions for the stereoselective synthesis of polysubstituted piperidinones
作者:Stephen G. Davies、Paul M. Roberts、Andrew D. Smith
DOI:10.1039/b701226h
日期:——
The efficiency and stereoselectivity of the conjugate addition of lithium (Z)- or (E)-beta-amino ester enolates, generated by lithium amide conjugate addition to an alpha,beta-unsaturated ester or deprotonation of a beta-amino ester, respectively, to a range of alpha,beta-unsaturated acceptors has been investigated. Deprotonation of a beta-amino ester with LDA, followed by conjugate addition to a chiral