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。
A New Polymer-Anchored Chiral Catalyst for Asymmetric Michael Addition Reactions
作者:G. Sundararajan、Prabagaran Narayanasamy
DOI:10.1021/ol006898e
日期:2001.2.8
affords polymers, onto which lithium and aluminum are incorporated via reaction with lithium aluminum hydride. The resulting insoluble polymers containing chiral lithium and aluminum active centers are quite effective for asymmetricMichaeladdition of nitro compounds, thiols, and amines. The optimized reaction conditions yield Michael adducts in good yield with high enantiomeric excesses.
Asymmetric Michael reactions of thiols with enones were catalyzed by a Sc(OTf)3–chiral bipyridine complex at room temperature in water without using any organic solvents, to afford the desired sulfides in high yields with high enantioselectivities.
Asymmetric Michael reactions and enantioselective protonations between enones and thiols were catalyzed by a Sc(OTf)3–chiral 2,2′-bipyridine complex in water. The remarkable governing of the enantioselectivity for simple introduction of protons despite their abnormally high mobility in water may provide us with new synthetic opportunities as well as significant chemical advances.
Magnesium‐Catalyzed Asymmetric Thia‐Michael Addition to α,β‐Unsaturated Ketones
作者:Joanna A. Jaszczewska‐Adamczak、Paulina Baczewska、Robert Bujok、Jacek Mlynarski
DOI:10.1002/adsc.202301414
日期:2024.3.19
chiral magnesium complexes in an asymmetric carbon-sulfur bond-forming reaction. Enantioselective and cost-effective methodology under mild condition for the thia-Michael addition, utilizing an in situ generated chiral dinuclear magnesium-ProPhenol complex, has been developed. The versatility of this protocol is demonstrated with a broad range of thiol nucleophiles and a wide selection of enones. Enantioenriched