An NHC–Cu complex catalyzed the asymmetricconjugateaddition (ACA) of various Grignard reagents to nonactivated α-substituted cyclic enones to give 2,3-dialkylated cyclopentanones and cyclohexanones. The Michael addition features the formation of a magnesium enolate intermediate. One-pot diastereoselective trapping of this enolate by alkyl, propargyl, allyl, and benzyl halides led to ketones with
Copper-Catalysed Conjugate Addition of Grignard Reagents to 2-Methylcyclopentenone and Sequential Enolate Alkylation
作者:Beatriz C. Calvo、Ashoka V. R. Madduri、Syuzanna R. Harutyunyan、Adriaan J. Minnaard
DOI:10.1002/adsc.201400085
日期:2014.6.16
The copper/Rev‐JosiPhos‐catalysed asymmetric conjugateaddition of Grignard reagents to 2‐methylcyclopentenone (1) provides 2,3‐disubstituted cyclopentanones in high yields and enantioselectivities, and good diastereoselectivities. Reaction of the in situ formed enolate with various alkylating reagents in the presence of 1,3‐dimethyltetrahydropyrimidine‐2(1H)‐one (DMPU) affords the corresponding products
Rhenium and ruthenium induced ring closing olefin metathesis to hydroazulenes
作者:Matthias F. Schneider、Heiko Junga、Siegfried Blechert
DOI:10.1016/0040-4020(95)00822-p
日期:1995.11
Several highly functionalized diolefins cyclize to hydroazulenes via olefin metathesis catalyzed either by CH3ReO31 or by the ruthenium catalyst synthesized by Grubbs.(2) We demonstrate the superiority of the ruthenium catalyst.