Organocatalytic Asymmetric Transfer Hydrogenation of Nitroolefins
摘要:
We describe a highly efficient and highly enantioselective Hantzsch ester mediated conjugate transfer hydrogenation of beta,beta-disubstituted nitroolefins that is catalyzed by a Jacobsen-type thiourea catalyst.
Efficient Cu-Catalyzed Asymmetric Conjugate Additions of Alkylzinc Reagents to Aromatic and Aliphatic Acyclic Nitroalkenes
作者:Dawn M. Mampreian、Amir H. Hoveyda
DOI:10.1021/ol0488338
日期:2004.8.1
Cu-catalyzed method for asymmetric conjugate addition (ACA) of alkylzinc reagents to acyclic disubstituted nitroalkenes is presented. Reactions are typically effected at ambient temperature in the presence of 2 mol % chiral dipeptide phosphine and 1 mol % (CuOTf)(2).C(6)H(6). Nitroalkenes bearing aromatic as well as aliphatic substituents readily undergo asymmetricadditions. [reaction: see text]
Convenient Catalytic, Enantioselective Conjugate Reduction of Nitroalkenes Using CuF<sub>2</sub>
作者:Constantin Czekelius、Erick M. Carreira
DOI:10.1021/ol048035h
日期:2004.11.1
We document the use of a new catalyst system for the enantioselectiveconjugatereduction of nitroalkenes utilizing commercially available CuF(2) and the bis-phosphine JOSIPHOS as a ligand. This new protocol not only facilitates ready access to a variety of optically active nitroalkanes, but the results provide also new insight into copper-catalyzed reactions. [reaction: see text]
Generality-Driven Catalyst Development: A Universal Catalyst for Enantioselective Nitroalkene Reduction
作者:Zihang Deng、Melanie A. Padalino、Julius E. L. Jan、Sangjun Park、Michael W. Danneman、Jeffrey N. Johnston
DOI:10.1021/jacs.3c12436
日期:2024.1.17
peptidomimetics. A single new organocatalyst provides high selectivity and substrate generality that is matched only by a combination of metal and organocatalysts. Within organocatalysis, this discovery breaks a 16-year monolithic paradigm, uncovering a powerful new scaffold for enantioselective reduction with behavior that suggests the recognition of a nitroethylene minimal catalaphile.
Cu-catalysed asymmetric 1,4-addition of Me3Al to nitroalkenes. Synthesis of (+)-ibuprofen
作者:Damien Polet、Alexandre Alexakis
DOI:10.1016/j.tetlet.2005.01.007
日期:2005.2
Trimethylaluminium undergoes enantioselective (ee up to 93%) copper-catalysed Michael addition to various nitroalkenes. Copper thiophenecarboxylate (CuTC) (2 mol %) and 4 mol% of a chiral phosphoramidite ligand are sufficient for a complete and clean reaction. The synthesis of (+)-ibuprofen is described with 82% ee. (C) 2005 Elsevier Ltd. All rights reserved.