In the probably concerted cycloadditions of the sterically hindered thiocarbonyl ylide 1 with fumaronitrile, maleonitrile, and dimethyl fumarate, the dipolarophile configuration is retained whereas retention/inversion 99:1 for dimethyl maleate (51 times less reactive than fumarate) signals a small involvement of a two-step pathway. The latter becomes dominant when two acceptor groups stabilize the
The first two-step 1,3-dipolar cycloadditions: non-stereospecificity
作者:Rolf. Huisgen、Grzegorz. Mloston、Elke. Langhals
DOI:10.1021/ja00280a053
日期:1986.10
On etudie les cycloadditions de sulfoniomethanures avec le dicyanofumarate de dimethyle et le fumarate de dimethyle
研究磺基甲烷的环加成反应 avec le dicyanofumarate dedimethyle et le fumarate dedimethyle
Further contributions to the stereospecificity of 1,3-dipolar cycloadditions of thiocarbonyl ylides
作者:Rolf Huisgen、Eike Langhals、Heinrich Nöth
DOI:10.1016/s0040-4039(00)85241-7
日期:1986.1
The stereospecific cycloadditions of thiobenzophenone S-methylide () to dimethyl 2,3-dicyanofumarate and of thiocarbonylylide to maleonitrile contribute to the separation of electronic (HO-LU energy distances) and steric effects in the borderline region of competing concerted and two-step processes.