The reactivity of the highly functionalized copper, zinc reagents RCu(CN)ZnI toward 1-haloalkynes and acetylenic esters
作者:Ming Chang P. Yeh、Paul Knochel
DOI:10.1016/s0040-4039(01)80511-6
日期:1989.1
The highlyfunctionalizedorganometallics RCu(CN)ZnI 1 react efficiently with 1-haloalkynes providing polyfunctionalized alkynes in high yields. This method has been used to prepare a pheromone of the Amathes c-nigrum in 3 steps and 64% overall yield. The reagents 1 also add in the presence of an excess of Me3SiCl to acetylenic esters to afford polyfunctionalized C—silylated ethylenic esters. In the
Preparation of functionalized dialkylzinc reagents via an iodine-zinc exchange reaction. Highly enantioselective synthesis of functionalized secondary alcohols
作者:Michael J. Rozema、AchyuthaRao Sidduri、Paul Knochel
DOI:10.1021/jo00033a008
日期:1992.3
Functionalized dialkylzincs are obtained by the reaction of polyfunctional alkyl iodides with Et2Zn in excellent yield. Their treatment with aldehydes, in the presence of the titanium catalyst 6, affords functionalized secondary alcohols with high enantioselectivity.
YEH, MING CHANG P.;KNOCHEL, PAUL, TETRAHEDRON LETT., 30,(1989) N6, C. 4799-4802
作者:YEH, MING CHANG P.、KNOCHEL, PAUL
DOI:——
日期:——
Cyclization Reaction of Cyano-Substituted Unsaturated Esters Prompted by Conjugate Addition of Organoborons
[reaction: see text] Unsaturated esters possessing a pendent cyano moiety react with B-Ar-9-BBNs in the presence of a rhodium(I) catalyst to give the five- and six-membered beta-enamino esters in good yield. An (oxa-pi-allyl)rhodium(I) intermediate, formed by initial conjugateaddition of an Ar-rhodium(I) species, undergoes a facile intramolecular addition to the cyano group to construct the carbocyclic