The highly enantioselective Michael addition of ketones to nitrodienes catalyzed by the efficient organocatalyst system of pyrrolidinyl-thioimidazole and chiral thioureido acid
The highlyenantioselectiveMichaeladdition reaction of ketones to nitrodienes was promoted efficiently by the accessible and fine-tunable organocatalytic system of pyrrolidinyl-thioimidazole and chiral thioureido acid. The corresponding adducts were afforded in good yields with high diastereoselectivities (up to 99 : 1) and excellent enantioselectivities (up to 99% ee).
Self‐assembled catalyst: A new kind of chiral supramolecular organocatalyst, self‐assembled from chiral amines and poly(alkene glycol)s, was developed. The resulting self‐assemblies were found to be highlyefficient in the asymmetriccatalysis of the unusual Diels–Alder reaction between cyclohexenones and nitrodienes, nitroenynes or nitroolefins, giving excellent chemo‐, regio‐ and enantioselectivities
N-Heterocyclic Carbene Catalyzed Homoenolate-Addition Reaction of Enals and Nitroalkenes: Asymmetric Synthesis of 5-Carbon-Synthon δ-Nitroesters
作者:Biswajit Maji、Li Ji、Siming Wang、Seenuvasan Vedachalam、Rakesh Ganguly、Xue-Wei Liu
DOI:10.1002/anie.201203449
日期:2012.8.13
Synthesizing synthons: The highly enantioselective title reaction is described. It employs catalytic amounts of N‐heterocyclic carbene precursors and transforms a broad range of nitroalkenes, such as nitrodienes, nitroenynes, and nitrostyrenes, through reaction with a broad range of enals, into δ‐nitroesters via homoenolate intermediates (see scheme).
Chiral Bifunctional Thiourea-Catalyzed Enantioselective Michael Addition of Ketones to Nitrodienes
作者:Hai Ma、Kun Liu、Fa-Guang Zhang、Chuan-Le Zhu、Jing Nie、Jun-An Ma
DOI:10.1021/jo901991v
日期:2010.3.5
Simple bifunctional thioureas, derived from the commercially available saccharides and chiral diamines, have been shown tunably to promote Michael-type addition of ketones to α,β−γ,δ-nitrodienes. The Michael adducts were obtained in good yields albeit with high enantioselectivites (84−99% ee). Furthermore, these products can be readily transformed into more useful molecules.