Readily available hydrogen bond catalysts for the asymmetric transfer hydrogenation of nitroolefins
作者:Jakob F. Schneider、Markus B. Lauber、Vanessa Muhr、Domenic Kratzer、Jan Paradies
DOI:10.1039/c1ob05059a
日期:——
focuses on readily accessible thiourea hydrogen bond catalysts derived from amino acids, whose steric and electronic features are modulated by their degree of substitution at the carbinol carbon center. These catalysts were applied in the asymmetric transfer hydrogenation of nitroolefins furnishing the chiral products in up to 99% yield and 86% enantiomeric excess. The proposed catalyst's mode of action
A highly efficient, iridium-catalyzed, enantioselectivehydrogenation of β,β-disubstituted nitroalkenes has been developed. Using a complex consisting of iridium and (S,S)-f-spiroPhos as the catalyst, a variety of β,β-disubstituted nitroalkenes were successfully hydrogenated to the corresponding chiral nitroalkanes with excellent enantioselectivities (up to 98% ee) and high turnover numbers (TON=1000)
Light-Enabled Enantiodivergence: Stereospecific Reduction of Activated Alkenes Using a Single Organocatalyst Enantiomer
作者:Theresa Hostmann、John J. Molloy、Kathrin Bussmann、Ryan Gilmour
DOI:10.1021/acs.orglett.9b04263
日期:2019.12.20
Light-enabled enantiodivergence is demonstrated in which the alkene substrate configuration is manipulated (E → Z) prior to organocatalytic reduction with a chiral thiourea and Hantzsch ester. This allows stereodivergent reduction to be regulated at the substrate level with high fidelity and mitigates the need for a second, enantiomeric catalyst (up to 93:07 and 95:5 er). The synthetic utility of this
Go catalytic! A highlyenantioselectivehydrogenation of β,β‐disubstituted nitroalkenes and isomeric mixtures of nitroalkenes by using a Rh/DuanPhos catalytic system under basic conditions has furnished a convenient approach to β‐chiral nitroalkanes, which are otherwise not so easy to make (see scheme).
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.