palladium‐catalyzed asymmetricallylicalkylation reaction with diorganozinc reagents, which displays broad functional group compatibility, is reported. This novel transformation hinges on a remarkableligandeffect which overrides the standard “umpolung” reactivity of allyl–palladium intermediates in the presence of dialkylzincs. Owing to its mild conditions, enantioselective allylicalkylations of racemic
Studies of the transition-state structure by the method of volumetric steric effects. Part 4. Transition state in Diels–Alder reactions of (E)-1-alkyl(alkoxy)-buta-1,3-dienes with alkyl acrylates
作者:Boris S. El'yanov、Svetlana K. Shakhova、Boris D. Polkovnikov、Lev F. Rar
DOI:10.1039/p29850000011
日期:——
A method of studying transition-state structures by analysis of volumetric steric effects is proposed. The method is used to reveal features of the steric structure of the transitionstate in Diels–Alderreactions. The structure has been found to change from one approximating the structure of the prereactional complex to that resembling the half-chair adduct as the diene substituent changes from methyl
Study of the effect of substituents and temperature on the regio- and stereoselectivity of diene condensation of 1-alkyl-substituted dienes with alkyl acrylates
作者:S. K. Shakhova、L. F. Rar、B. D. Polkovnikov、N. N. Vainberg、B. S. �l'yanov