The Copper Mediated Barbier Reactions of α,β-Unsaturated Ketones: Regioselective Conjugate and 1,2-Addition
摘要:
The one-pot reaction of isophorone and other alpha,beta-unsaturated ketones with alkyl and aryl halides in the presence of magnesium and a copper salt ("Barbier" conditions) leads to the regiospecific formation of 1,4-addition products; the use of lithium leads to regioselective 1,2-addition.
Organomanganese (II) reagents XVI1: copper-catalyzed 1,4-addition of organomanganese chlorides to conjugated enones
作者:Gérard Cahiez、Mouad Alami
DOI:10.1016/s0040-4039(00)99434-6
日期:1989.1
Copper-catalyzed conjugate addition of organomanganese chlorides to conjugated enones in THF, at 0°C, leads to the 1,4 addition products in high yields. The scope of the reaction is very large and the results are generally better than those obtained from organomagnesium compounds in the presence of a copper salt as well as from organocopper or cuprate reagents. Furthermore organomanganese chlorides are indisputably
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.
Trialkylsilyl chlorides, particularly in combination with hexamethylphosphoramide or 4-dimethylaminopyridine, dramatically accelerates the conjugate addition of catalytic and stoichiometric organocopperreagents onto enones, enals, and enoates, in which very high degrees of stereo- and chemoselectivities were observed.
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。
Reaction of lithium dialkylcuprates with β-alkoxy and β-alkylthio αβ-unsaturated carbonyl compounds
作者:Gary H. Posner、Daniel J. Brunelle
DOI:10.1039/c39730000907
日期:——
β-Alkoxy- and β-alkylthio-αβ-ethylenic esters and ketones are converted in high yield into β-alkyl-αβ-ethylenic esters and into ββ-dialkyl ketones using lithium dialkylcuprate reagents.