Zur Kenntnis organischerLewis-S�uren, 36.Cis?trans-Gleichgewichte und Konformationen von 2,(x)-Dialkyl-1-dicyanomethylencyclohexanen. Wahlweise einfache Darstellung dercis- odertrans-Formen
Zur Kenntnis organischerLewis-S�uren, 36.Cis?trans-Gleichgewichte und Konformationen von 2,(x)-Dialkyl-1-dicyanomethylencyclohexanen. Wahlweise einfache Darstellung dercis- odertrans-Formen
On the origin of the stereoselectivity of hydrazone alkylations. Investigation of aggregation effects and solution kinetics
作者:Robert A. Wanat、David B. Collum
DOI:10.1021/ja00293a043
日期:1985.4
On montre que les stereoselectivites des alkylations d'hydrazones ne derivent pas des effets d'agregation des anions mais de l'alkylation stereoselective de derives monomeres du lithium bis-solvates
在 montre que les 立体选择性去烷基化 d'hydrazones ne 衍生的 pas des effets d'agregation des anions mais de l'烷基化立体选择性去衍生单体 du 锂双溶剂化物
Epimerization and kinetic resolution in copper-catalyzed enantioselective 1,4-additions of organozinc reagents to 6-substituted cyclohex-2-enones
Enantioselective 1,4-addition reactions of diethyl-, dimethyl-, and di-n-butylzinc to 6-methylcyclohex-2-enone (1) and 6-t-butylcyclohex-2-enone (4), catalyzed by Cu(OTf)2 and phosphoramidites L1–L4 were examined. The additions to enone 1 proceeded with high enantioselectivity; by acid- or base-catalyzed epimerization, adduct (S,S)-2 can be obtained from racemic 1 in diastereo- and enantiomerically