1021955-33-8Relevant articles and documents
Chiral relay in NHC-mediated asymmetric β-lactam synthesis I; substituent effects in NHCs derived from (1R,2R)-cyclohexane-1,2-diamine
Duguet, Nicolas,Donaldson, Adele,Leckie, Stuart M.,Douglas, James,Shapland, Peter,Brown, Thomas B.,Churchill, Gwydion,Slawin, Alexandra M.Z.,Smith, Andrew D.
experimental part, p. 582 - 600 (2010/08/19)
The synthesis of a range of C2-symmetric imidazolinium salts from (1R,2R)-cyclohexane-1,2-diamine, and an evaluation of the reactivity and asymmetric induction of the derived NHCs as catalysts for the asymmetric synthesis of β-lactams, is reported. In this series, optimal enantioselectivity (up to 70% ee) is observed using N-benzyl or N-1-naphthylmethyl-substituted NHCs, consistent with a chiral relay effect operating to dictate the stereochemical outcome of this reaction.
N-Heterocyclic carbene catalysed β-lactam synthesis
Duguet, Nicolas,Campbell, Craig D.,Slawin, Alexandra M. Z.,Smith, Andrew D.
supporting information; experimental part, p. 1108 - 1113 (2009/02/05)
N-Heterocyclic carbenes promote the formal [2+2] cycloaddition of ketenes with N-tosyl imines to give the corresponding β-lactams in good to excellent isolated yields; chiral NHCs give β-lactams in high e.e. after crystallisation.
