Acidic-functionalized ionic liquid as an efficient, green and reusable catalyst for hetero-Michael addition of nitrogen, sulfur and oxygen nucleophiles to α,β-unsaturated ketones
作者:Feng Han、Lei Yang、Zhen Li、Chungu Xia
DOI:10.1039/c1ob06346d
日期:——
A series of acidic-functionalized ionic liquids were synthesized and applied to the hetero-Michael addition of nitrogen, sulfur and oxygen nucleophiles to α,β-unsaturated ketones under solvent-free conditions. Notably, 1-methylimidazoliump-toluenesulfonic ([Hmim]OTs) was found to be the most efficient catalyst and could realize âhomogeneous catalysis, two-phase separationâ. Additionally, the catalytic system has wide substrate scope and good to excellent yields (up to 99%) could be obtained at room temperature.
Potassium phosphate or silica sulfuric acid catalyzed conjugate addition of thiols to α,β-unsaturated ketones at room temperature under solvent-free conditions
sulfuric acid have been found to be useful and highly efficient catalysts for conjugateaddition of thiols to α,β-unsaturated ketones undersolvent-freeconditions, at room temperature. Silica sulfuric acid (SSA) was found to be suitable for electron-deficient enones while potassium phosphate was found to effect thia-Michael addition with both, electron-deficient as well as electron-rich conjugated ketones
Asymmetric ruthenium-catalyzed 1,4-additions of aryl thiols to enones
作者:Andrei Bădoiu、Gerald Bernardinelli、Céline Besnard、E. Peter Kündig
DOI:10.1039/b918877k
日期:——
bind and activate α,β-unsaturated carbonyl compounds for cycloadditionreactions. These mild Lewisacidscatalyzeasymmetric 1,4-addition reactions of aryl thiols to enones with product selectivities up to 87% ee. 31P NMR experiments provide an insight into the intricate equilibria governing the reaction mechanism. The absolute configuration of the major products indicates enones to react in the syn-s-trans
定义明确,稳定的单点绑定 钌配合物1和2选择性地结合并活化α,β-不饱和羰基化合物以进行环加成反应。这些温和的路易斯酸催化芳基硫醇与烯酮的不对称1,4-加成反应,产物选择性高达ee的87%。31 P NMR实验提供了控制反应机理的复杂平衡的见解。主要产品的绝对构型表示烯酮的反应合成- S ^ -反式方向。基于Ru配合物的X射线结构的模型可用于合理化选择性。
Asymmetric synthesis based on chiral diamines having pyrrolidine ring
作者:Teruaki Mukaiyama
DOI:10.1016/s0040-4020(01)93286-7
日期:——
Various highly stereoselective asymmetric reactions based on chiral diamines having pyrrolidine ring are described. Some of these reactions have been successfully applied to the syntheses of natural products.
Green Protocol for Conjugate Addition of Thiols to α,β-Unsaturated Ketones Using a [Bmim]PF<sub>6</sub>/H<sub>2</sub>O System
作者:J. S. Yadav、B. V. S. Reddy、Gakul Baishya
DOI:10.1021/jo034335l
日期:2003.9.1
Alpha,beta-unsaturated ketones undergo conjugate addition rapidly with thiols in a hydrophobic ionic liquid [bmim]PF(6)/H(2)O solvent system (2:1) in the absence of any acid catalyst to afford the corresponding Michael adducts in high to quantitative yields with excellent 1,4-selectivity under mild and neutral conditions. The enones show enhanced reactivity in ionic liquids, thereby reducing reaction