Kinetics of [2+2] cycloadditions of 2,2-bis(trifluoromethylethylene-1,1-dicarbonitrile with enol ethers, 1,1-dimethylbutadiene, and allyltrimethylsilane
作者:Reinhard Brückner、Rolf Huisgen
DOI:10.1016/0040-4039(90)80124-5
日期:1990.1
The rate constant with ethyl vinylether is enhanced by α-donor substitutents whereas gb-methyl groups strongly retard by steric hindrance. The title compound (BTF) is 2400 times more active than TCNE towards ethyl vinylether in benzene. The rates of the title reactions Increase 70- to 2300-fold with solvent polarity.
[2+2] cycloadditions of 2,2-bis(trifluoromethyl)ethylene-1,1-dicarbonitrile with enol ethers, 1,1-dimethylbutadiene, and allyltrimethylsilane
作者:Rolf Huisgen、Reinhard Brückner
DOI:10.1016/0040-4039(90)80123-4
日期:1990.1
Vinylethers and the title compound (BTF) form cyclobutanes via 1,4-dipoles which can be intercepted with ethanol or acetic acid. Cis- and trans-1-ethoxypropene react with BTF nonstereospecifically in agreement with a stepwise mechanism. 1,1-Dimethylbutadiene or allyltrimethylsilane undergo [2 + 2] cycloadditions with BTF, too.