Highly selective, kinetically controlled enolate formation using lithium dialkylamides in the presence of trimethylchlorosilane
作者:E.J. Corey、Andrew W. Gross
DOI:10.1016/s0040-4039(00)99920-9
日期:1984.1
The deprotonation of ketones and esters with lithium dialkylamides in the presence of trimethylchlorosilane leads to enhanced selectivity for the kinetically generated enolate. Lithium -octyl--butylamide is shown to be superior to lithiumdiisopropylamide in the regio-selective generation of enolates and in the stereoselective formation of enolates.
The Kharasch reaction revisited: CuX3Li2-catalyzed conjugate addition reactions of Grignard reagents
作者:Manfred T. Reetz、Alois Kindler
DOI:10.1016/0022-328x(95)05699-p
日期:1995.10
The conjugate addition of Grignardreagents RMgX to α,β-unsaturated ketones and esters is effectively catalyzed by soluble copper ate-complexes of the type CuX3Li2, e.g. CuI · 2LiCl. In the presence of Me3SiCl the corresponding ketone enolsilanes are formed in high yield and selectivity. Diasteroselectivity in the case of chiral ketones is similar to that observed by using stoichiometric amounts of
格氏试剂RMgX向α,β-不饱和酮和酯的共轭加成可通过CuX 3 Li 2类型的可溶性铜酸酯络合物(例如CuI·2LiCl )有效地催化。在Me 3 SiCl存在下,可以高产率和高选择性形成相应的酮烯醇硅烷。在手性酮的情况下,非对映选择性类似于通过使用化学计量的铜酸盐R 2 CuLi所观察到的非对映选择性。因此,CuX 3 Li 2催化的格氏试剂的1,4-加成可能是工业上可行的方法。
Me3SiCl accelerated conjugate addition of stoichiometric organocopper reagents
Chlorotrimethylsilane, particularly if combined with hexamethylphosphoric triamide or 4-dimethylaminopyridine, strongly promote the conjugate addition of stoichiometric organocopperreagents.
A directing effect of neighboring aromatic groups on the regiochemistry of formation and stereochemistry of alkylation and bromination of ketone lithium enolates. Evidence for lithium-arene coordination and dramatic effect of copper(I) in controlling stereochemistry and limiting polyalkylation