On the mechanism of the copper-catalyzed enantioselective 1,4-addition of grignard reagents to α,β-unsaturated carbonyl compounds
On the mechanism of the copper-catalyzed enantioselective 1,4-addition of grignard reagents to α,β-unsaturated carbonyl compounds
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DOI：
10.1021/ja0585634
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发表时间：
2006-07-19
影响因子：
15
通讯作者：
Feringa, Ben L.
中科院分区：
文献类型：
--
作者：
Harutyunyan, Syuzanna R.;Lopez, Fernando;Feringa, Ben L.
通过动力学、光谱和电化学分析，探讨了手性二茂铁二膦铜配合物促进格氏试剂与 α,β-不饱和羰基化合物发生对映选择性 1,4-加成的机理。在这些研究的基础上，提出了活性催化剂的结构。已经检查了溶剂、卤化铜和格氏试剂的作用。动力学研究支持还原消除作为限速步骤，其中涉及手性催化剂、底物和格氏试剂。热力学活化参数由反应速率的温度依赖性确定。讨论了假定的活性物质和反应的催化循环。
The mechanism of the enantioselective 1,4-addition of Grignard reagents to alpha,beta-unsaturated carbonyl compounds promoted by copper complexes of chiral ferrocenyl diphosphines is explored through kinetic, spectroscopic, and electrochemical analysis. On the basis of these studies, a structure of the active catalyst is proposed. The roles of the solvent, copper halide, and the Grignard reagent have been examined. Kinetic studies support a reductive elimination as the rate-limiting step in which the chiral catalyst, the substrate, and the Grignard reagent are involved. The thermodynamic activation parameters were determined from the temperature dependence of the reaction rate. The putative active species and the catalytic cycle of the reaction are discussed.