Modularly Evolved 2-AminoDMAP/Squaramides as Highly Active Bifunctional Organocatalysts in Michael Addition
作者:Murat Işık、M. Yagiz Unver、Cihangir Tanyeli
DOI:10.1021/jo5022597
日期:2015.1.16
We report a new family of chiral bifunctional acid/base type organocatalysts, 2-aminoDMAP/Squaramides, which are proved to be highly active (1 mol % cat. loading) promoters in conjugate addition of dibenzoylmethane to various trans-β-nitroalkenes. Steric demand of the catalysts was clearly seen by a set-by-set modulation of the squaramide unit through electronic and steric factors. The synergistic
Molecular Engineering of β‐Substituted Oxoporphyrinogens for Hydrogen‐Bond Donor Catalysis
作者:Mandeep K. Chahal、Daniel T. Payne、Yoshitaka Matsushita、Jan Labuta、Katsuhiko Ariga、Jonathan P. Hill
DOI:10.1002/ejoc.201901706
日期:2020.1.9
Beta functionalization of oxoporphyrinogens as H‐bonddonor catalysts with binding site designed for dual activation of substrates is reported. Introduction of the β‐substituents enables the catalysis of 1,4‐conjugate additions, sulfa‐Michael additions and Henry/aza‐Henry reactions at low catalyst loadings (≤ 1 mol‐%) under mild conditions.
Michaeladditions of different aldehydes and ketones to β-nitrostyrene and 2-(β-nitrovinyl)thiophene in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF6) were studied. β-Nitrostyrene was a better acceptor than 2-(β-nitrovinyl)thiophene, in terms of both reactivity and selectivity. Aldehydes proved to be better donors than ketones, which were themselves better than β-diketones. L-proline proved
Michael Addition of Active Methylene Compounds to α,β-Unsaturated Carbonyl Compounds under the Influence of Molecular Sieves in Dimethyl Sulfoxide
作者:Tomoko Kakinuma、Ryoichi Chiba、Takeshi Oriyama
DOI:10.1246/cl.2008.1204
日期:2008.12.5
The Michael addition of active methylene compounds to α,β-unsaturated carbonyl compounds in the presence of MS 4A in dimethyl sulfoxide proceeds smoothly to afford the corresponding 1,4-addition pr...
(NetState-I) with a fuel acid reversibly afforded the protonated cyclam and the silver(I)-loaded crown ether (NetState-II). While NetState-I was catalytically OFF, a base-catalysed Michael addition and a silver(I)-catalysed oxime cyclisation reaction was pulsed under dissipative conditions in NetState-II.
用燃料酸对冠醚受体和负载银 ( I ) 的环芳烃衍生物 ( NetState-I) 进行可逆处理,得到质子化的环芳烃和负载银 ( I ) 的冠醚 ( NetState-II)。当 NetState-I 被催化关闭时,碱催化的迈克尔加成和银 ( I ) 催化的肟环化反应在 NetState-II 的耗散条件下进行脉冲。