Chiral relay in NHC-mediated asymmetric β-lactam synthesis II; asymmetry from NHCs derived from acyclic 1,2-diamines
摘要:
The synthesis of a range of imidazolinium salts derived from acyclic 1,2-diamines, and an evaluation of the reactivity and asymmetric induction of the corresponding NHCs as catalysts for the asymmetric synthesis of beta-lactams, is reported. An N-methyl-substituted NHC derived from (1R,2R)-1,2-diphenylethanediamine shows optimal reactivity and enantioselectivity in this series, in contrast to that observed with NHCs derived from (1R,2R)-cyclohexane-1,2-diamine. (C) 2010 Elsevier Ltd. All rights reserved.
Chiral relay in NHC-mediated asymmetric β-lactam synthesis II; asymmetry from NHCs derived from acyclic 1,2-diamines
摘要:
The synthesis of a range of imidazolinium salts derived from acyclic 1,2-diamines, and an evaluation of the reactivity and asymmetric induction of the corresponding NHCs as catalysts for the asymmetric synthesis of beta-lactams, is reported. An N-methyl-substituted NHC derived from (1R,2R)-1,2-diphenylethanediamine shows optimal reactivity and enantioselectivity in this series, in contrast to that observed with NHCs derived from (1R,2R)-cyclohexane-1,2-diamine. (C) 2010 Elsevier Ltd. All rights reserved.
Regioselective reductive transamination of peptidic amides enabled by a dual Zr(IV)–H catalysis
作者:Jian-Tao Tang、Yu Gan、Xuejiao Li、Baihua Ye
DOI:10.1016/j.chempr.2022.11.002
日期:2022.12
is a common structural motif of peptides and biologically active molecules, is a highly attractive target for catalytic transformations. Despite its high synthetic potential, the chemical inertness of the amide bond, owing to its resonance stabilization, has rendered this approach challenging. Existing catalytic modes essentially include metal-catalyzed carbon–nitrogen bond activation, transamidation
Chiral relay in NHC-mediated asymmetric β-lactam synthesis II; asymmetry from NHCs derived from acyclic 1,2-diamines
作者:Nicolas Duguet、Adele Donaldson、Stuart M. Leckie、Eddy A. Kallström、Craig D. Campbell、Peter Shapland、Thomas B. Brown、Alexandra M.Z. Slawin、Andrew D. Smith
DOI:10.1016/j.tetasy.2010.03.002
日期:2010.3
The synthesis of a range of imidazolinium salts derived from acyclic 1,2-diamines, and an evaluation of the reactivity and asymmetric induction of the corresponding NHCs as catalysts for the asymmetric synthesis of beta-lactams, is reported. An N-methyl-substituted NHC derived from (1R,2R)-1,2-diphenylethanediamine shows optimal reactivity and enantioselectivity in this series, in contrast to that observed with NHCs derived from (1R,2R)-cyclohexane-1,2-diamine. (C) 2010 Elsevier Ltd. All rights reserved.