A variety of alkylidenecyclopropanes bearing various substituents on their cyclopropane ring were obtained by the titanocene(II)-promoted reaction of 1,1-dichlorocyclopropane derivatives with carbonyl compounds including esters and lactones. (C) 2007 Elsevier Ltd. All rights reserved.
A Catalytic Enantioselective Conjugate Addition of Cyanide to Enones
作者:Yuta Tanaka、Motomu Kanai、Masakatsu Shibasaki
DOI:10.1021/ja801201r
日期:2008.5.1
The first synthetically useful catalytic enantioselectiveconjugateaddition of cyanide to enones is described. The optimized conditions involved a Gd catalyst (5 or 10 mol %) derived from ligands 3 or 4 and a 1:1 ratio of TBSCN and 2,6-dimethylphenol. The reaction exhibited excellent to high enantioselectivity and a wide substrate scope. Moreover, the 1,4-adduct was exclusively produced over the 1
Titanocene(II)-Promoted Multicomponent Reactions Utilizing Alkynyl Sulfones, Alkenyl Sulfones, and Carbonyl Compounds: A Novel Method for the Synthesis of Vinylallenes
Titanocene(II)-promoted cross coupling of alkynyl- and (Z)-alkenyl sulfones affords alpha-(phenylsulfonyl)alkenyltitanium species. Further treatment of these species with the titanocene(II) reagent generates titanium vinylvinylidene complexes, which react with carbonyl compounds in one pot to produce substituted vinylallenes with complete stereoselectivity. By using alpha,beta-unsaturated ketones,
Treatment of 1,1-dichloroalk-1-enes with Cp2Ti[P(OEt)3]2 produced organotitanium species, which afford allenes on treatment with aldehydes and ketones.
用Cp2Ti[P(OEt)3]2处理1,1-二氯烯烃,生成有机钛物种,与醛和酮反应生成烯烃。
REICH H. J.; OLSON R. E., J. AMER. CHEM. SOC., 1980, 102, NO 4, 1423-1424
A variety of alkylidenecyclopropanes bearing various substituents on their cyclopropane ring were obtained by the titanocene(II)-promoted reaction of 1,1-dichlorocyclopropane derivatives with carbonyl compounds including esters and lactones. (C) 2007 Elsevier Ltd. All rights reserved.