New Highly Nucleophilic and Practically Accessible Chlorocarbenoids for Carbonyl Olefination
作者:Chia-Chung Tsai、Ching-Ting Chien、Yu-Cheng Chang、Huan-Chang Lin、Tu-Hsin Yan
DOI:10.1021/jo050455c
日期:2005.7.1
bimetallic species resulted in the generation of a highly nucleophilic and practically convenient chloromethylenetitanium complex, which efficiently effected condensation even with enolizable or inert carbonyl compounds, such as sterically congested ketones, to provide vinyl chloride compounds.
[reaction: see text] This Mg-TiCl4-promoted CH2-transfer reaction of CH2Cl2 represents an extremely simple, practical, and efficient methylenation of a variety of ketones and aldehydes, especially in enolizable or sterically hindered ketones such as 2,2-dimethylcyclohexanone, camphor, and fenchone.
cis-3,5-Cyclohexadiene-1,2-diol derivatives: facial selectivity in their Diels–Alder reactions with ethylenic, acetylenic and azo dienophiles
作者:Sunny M. Ogbomo、D. Jean Burnell
DOI:10.1039/b607938e
日期:——
The Diels-Alderreactions of maleimide with the acetonide derivative (6a) of cis-3,5-cyclohexadiene-1,2-diol (1a) in various solvents showed facial selectivities ranging from 1 : 1 to 1 : 9. The same derivative 6a reacted in benzene with ethylenic dienophiles with generally modest facial selectivity, but acetylenic dienophiles added exclusively anti to the oxygen functions of 6a. Dimerization of cyclic