A new allylation reaction of carbonyl compounds using allenes
is described; homoallylic alcohols were obtained in moderate to good yields
from aryl iodides, allenes and carbonyl compounds and an excellent
diastereoselection was exhibited when 2-hydroxycyclohexanone was
employed.
Three-component bimetallic (Pd/In) mediated cascade allylation of C=X functionality
作者:Laura A.T Cleghorn、Ian R Cooper、Colin W.G Fishwick、Ronald Grigg、William S MacLachlan、Marcello Rasparini、Visuvanathar Sridharan
DOI:10.1016/j.jorganchem.2003.09.047
日期:2003.12
A new general three-component Pd/In bimetallic cascade reaction with four synthetic variants involving aryliodides, allenes and C=X compounds affording homoallylic alcohols/amines as products is described and exemplified for Class 1 processes (intermolecular Pd–intermolecular In steps). Remarkable increases in yield and reaction rates were observed in the presence of amine additives. Excellent diastereoselection
Radical homopolymerization of linear α-olefins has been developed. The success of this polymerization relies on the high efficiency of 1,4-cyano group migration. This approach can be applied to homopolymerize α- substituted styrenes or acrylates. As a chain transfer agent, a symmetric allylic sulfide is created to regulate the propagating thiyl radicals over the polymerization process.
Selective mono- and polymethylene homologations of copper reagents using (iodomethyl)zinc iodide
作者:AchyuthaRao Sidduri、Michael J. Rozema、Paul Knochel
DOI:10.1021/jo00062a010
日期:1993.5
A wide range of unsaturated aryl-, alkenyl-, alkynylcopper compounds can be selectively homologated by a methylene unit using (iodomethyl)zinc iodide or bis(iodomethyl)zinc. These reactions allow the generation of mixed allylic zinc-copper compounds which can be efficiently trapped with carbonyl compounds. An application to a general preparation of functionalized alpha-methylene-gamma-butyrolactones is described. The homologation of alkynylcoppers with (iodomethyl)zinc iodide allows a one-pot preparation of propargylic copper reagents which in the presence of a carbonyl compound provide various homopropargylic alcohols in excellent yields. In the absence of an electrophile, a clean quadruple methylene homologation of alkynylcoppers occurs to furnish dienic copper reagents. The homologation of other types of copper reagents is also possible, and carbanions at the alpha-position to amines as well as homoenolates of aldehydes or ketones can also be prepared by this method.