Although quaternary ammonium and phosphonium salts are known as important catalysts in phase-transfer catalysis, the catalytic ability of tertiary sulfonium salts has not yet been well demonstrated. Herein, we demonstrate...
Lewis Acid Catalysis in Supercritical Carbon Dioxide. Use of Scandium Tris(heptadecafluorooctanesulfonate) as a Lewis Acid Catalyst in Diels-Alder and Aza Diels-Alder Reactions
Diels-Alderreactions of carbonyl dienophiles with dienes and aza Diels-Alderreactions of imines with a diene have been successfully carried out using scandium tris(heptadecafluorooctanesulfonate) (Sc(OSO2C8F17)3) as a Lewis acid catalyst in supercritical carbon dioxide (scCO2). It was revealed that the length of perfluorocarbon chains of the scandium catalyst was an essential factor for the catalytic
Bis-selenonium Cations as Bidentate Chalcogen Bond Donors in Catalysis
作者:Xinxin He、Xinyan Wang、Ying-Lung Steve Tse、Zhihai Ke、Ying-Yeung Yeung
DOI:10.1021/acscatal.1c03622
日期:2021.10.15
Lewisacids are frequently employed in catalysis but they often suffer from high moisture sensitivity. In many reactions, catalysts are deactivated because of the problem that strong Lewisacids also bond to the products. In this research, hydrolytically stable bidentateLewisacid catalysts derived from selenonium dicationic centers have been developed. The bis-selenonium catalysts are employed in
A piperidine‐derived tetraalkylammonium salt with a non‐coordinating counteranion worked as an effective hydrogen‐bonding catalyst in an aza‐Diels–Alder reaction of imines and a Danishefsky diene. The hydrogen‐bonding interaction between the ammonium salt and an imine was observed as part of a 1H NMR titration study.
哌啶衍生的四烷基铵盐与非配位抗衡阴离子在亚胺和Danishefsky二烯的aza-Diels-Alder反应中作为有效的氢键催化剂。在1 H NMR滴定研究中,观察到了铵盐和亚胺之间的氢键相互作用。
A New Approach to Di- and Tetrasubstituted 2,3-Dihydropyridin-4(1H)-ones through Aza-Diels-Alder Reaction Promoted by Silicon Tetrachloride
作者:Antonio Massa、Vincenzo de Sio、Rosaria Villano、M. Acocella、Laura Palombi、Giusi Sellitto、Antonella Peduto、Rosanna Filosa、Paolo De Capraris、Arrigo Scettri
DOI:10.1055/s-0028-1087677
日期:2009.2
Silicon tetrachloride promotes an aza-Diels-Alderreaction with a range of imines and Danishefsky’s diene or an alkylated derivative, giving the desired products in good to excellent yields. aza-Diels-Alderreaction - heterocycles - silicon tetrachloride