Mechanistic Investigation of the Enantioselective Intramolecular Stetter Reaction: Proton Transfer Is the First Irreversible Step
作者:Jennifer L. Moore、Anthony P. Silvestri、Javier Read de Alaniz、Daniel A. DiRocco、Tomislav Rovis
DOI:10.1021/ol200256a
日期:2011.4.1
A study on the mechanism of the asymmetric intramolecular Stetter reaction is reported. This investigation includes the determination of the rate law, kinetic isotope effects, and competition experiments. The reaction was found to be first order in aldehyde and azolium catalyst or free carbene. A primary kinetic isotope effect was found for the proton of the aldehyde. Taken together with a series of
Synthesis of (1R,2R)-DPEN-derived triazolium salts and their application in asymmetric intramolecular Stetter reactions
作者:Min-Qiang Jia、Yi Li、Zi-Qiang Rong、Shu-Li You
DOI:10.1039/c1ob00025j
日期:——
A series of novel chiral triazolium salts has been synthesized from readily available (1R,2R)-DPEN and found to be efficient for the enantioselective intramolecular Stetter reaction. With 10 mol% of the catalyst, the intramolecular Stetter reaction was realized in excellent yields with up to 97% ee.
Novel chiral N-heterocycliccarbenes derived from (−)-β-pinene have been synthesized and used as efficient catalysts for the intramolecular Stetterreaction. Mono-, di-, and trisubstituted 4-chromanone derivatives have been obtained almost quantitatively and with high enantioselectivity up to 99:1 er.
d-Camphor-Derived Triazolium Salts for Enantioselective Intramolecular Stetter Reactions
作者:Shu-Li You、Zi-Qiang Rong、Yi Li、Gui-Qiu Yang
DOI:10.1055/s-0030-1259732
日期:2011.4
Chiral triazolium salts based on the camphor scaffold have been found highly efficient for the asymmetric intramolecular Stetter reaction. With 10 mol% of the catalyst, the desired products were obtained in excellent yields with up to 97% ee.
Design and synthesis of novel chiral dihydroimidazolium cyclophanes as N-heterocyclic carbene precatalysts
作者:Ting Lu、Liuqun Gu、Qiang Kang、Yugen Zhang
DOI:10.1016/j.tetlet.2012.09.116
日期:2012.11
A series of novel diphenyl ethylenediamine (DPEN) derived C-2 symmetric dihydroimidazolium cyclophanes were designed and synthesized as organo NHC precatalysts. The resultant organo NHC-catalyzed reactions with superior enantioselectivity than traditional C-2 dihydroimidazolidine NHCs as exemplified by NHC-catalyzed asymmetric intramolecular Stetter reactions. (C) 2012 Elsevier Ltd. All rights reserved.