Synthesis of pyrrolidine-3-carboxylic acid derivatives <i>via</i> asymmetric Michael addition reactions of carboxylate-substituted enones
作者:Feng Yin、Ainash Garifullina、Fujie Tanaka
DOI:10.1039/c7ob01484h
日期:——
concisely synthesize highly enantiomerically enriched 5-alkylsubstituted pyrrolidine-3-carboxylic acids, organocatalytic enantioselective Michael addition reactions of 4-alkyl-substituted 4-oxo-2-enoates with nitroalkanes have been developed. Using the developed reaction method, 5-methylpyrrolidine-3-carboxylic acid with 97% ee was obtained in two steps.
Catalyst-Controlled, Enantioselective, and Diastereodivergent Conjugate Addition of Aldehydes to Electron-Deficient Olefins
作者:S. B. Jennifer Kan、Hiroki Maruyama、Matsujiro Akakura、Taichi Kano、Keiji Maruoka
DOI:10.1002/anie.201705546
日期:2017.8.1
A chiral-amine-catalyzed enantioselective and diastereodivergent method for aldehyde addition to electron-deficient olefins is presented. Hydrogen bonding was used as a control element to achieve unusual anti selectivity, which was further elucidated through mechanistic and computational studies.
AbstractA highly efficient N,N′‐dioxide–scandium(III) complex catalytic system has been developed for the asymmetric vinylogous Michael reaction of α‐angelica lactone and its derivatives to α,β‐unsaturated γ‐keto esters, affording the corresponding γ,γ‐disubstituted butenolide products in moderate to good yields (up to 93%) with high dr (up to >19:1) and ee values (up to 97%) under mild reaction conditions.magnified image
Umsetzungen mit Nitroenaminen, XII. Umsetzung von Estern und Lactonen mit Nitroenaminen
作者:Holger Lerche、Dieter König、Theodor Severin
DOI:10.1002/cber.19741070511
日期:1974.5
Ester von Carbonsäuren sowie Lactone mit α-ständiger Methylen-Gruppe lassen sich über die Lithium-Salze mit 1-Dimethylamino-2-nitroäthylen oder 1-Dimethylamino-2-nitro-1-propen zu aci-Nitroäthyliden- bzw. aci-Nitropropyliden-Derivaten umsetzen (3 + 4 5). Die Verbindungen 5d – k gehen auf Kieselgel in die Ketoester 9d – k über.