2'-position have been used in general protonations leading to reagent-controlled selectivity enhancements: up to 96:4 for the gamma/alpha-protonation of unsymmetrically substituted allyl anions, up to 97:3 for the protonation of cyclohexylanions generating preferentially the thermodynamically less stable cis-products. In order to allow a general, reagent-controlled protonation the acidity of the protonating
Chemistry of alkali metal-unsaturated hydrocarbon adducts
作者:John J. Eisch、Goutam Gupta
DOI:10.1016/s0022-328x(00)83269-6
日期:1979.3
The chemical behavior of alkali metal adducts of α,β-unsaturated organosilanes was investigated by generating the adducts with lithium or potassium metal in donor solvents at −78°C and studying the ensuing reduction, bimolecular coupling, cleavage and isomerization processes. Chosen for study were the triphenylvinyl derivatives of silicon, germanium and tin, as well as other vinyl-, phenyl-, allyl-
Modular Ni(0)/Silane Catalytic System for the Isomerization of Alkenes
作者:Kiana E. Kawamura、Alison Sy-min Chang、Daryl J. Martin、Haley M. Smith、Parker T. Morris、Amanda K. Cook
DOI:10.1021/acs.organomet.2c00010
日期:2022.2.28
versatile catalyticsystem that is effective for the formation of internal alkenes with high yield and selectivity for the E-alkene. The use of silanes as mild activators enables isomerization of substrates with a variety of functional groups, including acid-labile groups. The broad substrate scope, enabled by catalyst design, makes this catalyticsystem a strong candidate for use in tandem catalytic applications
The bromination, debromination and debromosilylation of silylstyrenes and other vinylsilanes
作者:A.G. Brook、J.M. Duff、W.F. Reynolds
DOI:10.1016/s0022-328x(00)85083-4
日期:1976.11
trans-triphenylsilylstyrene, it is shown that bromination and debromination of silylstyrenes occur with syn stereochemistry, and that debromosilylation occurs with anti stereochemistry in polar solvents. Differentstereochemistries may prevail with other vinylsilanes. Other elimination and substitution reactions are also described.