New access to Di-exo-methylenecyclobutanes via [2 + 2] cycloaddition of 3-methylthio-4-trimethylsilyl-1,2-butadiene with alkenes mediated by a Lewis acid
摘要:
Methylthio-substituted allenylmethylsilane, a kind of allylsilane, undergoes only [2 + 2] cycloaddition reaction with alkenes mediated by a Lewis acid to afford the corresponding methylenecyclobutanes which are readily converted to di-exo-methylenecyclobutanes by rite sequential oxidation-1,2-elimination in good yield. Di-exo-methylenecyclobutane is also successfully applied to construct a bicyclo[5.2.0]nonenone skeleton by the reaction with 2-oxyallyl cation.
New access to Di-exo-methylenecyclobutanes via [2 + 2] cycloaddition of 3-methylthio-4-trimethylsilyl-1,2-butadiene with alkenes mediated by a Lewis acid
摘要:
Methylthio-substituted allenylmethylsilane, a kind of allylsilane, undergoes only [2 + 2] cycloaddition reaction with alkenes mediated by a Lewis acid to afford the corresponding methylenecyclobutanes which are readily converted to di-exo-methylenecyclobutanes by rite sequential oxidation-1,2-elimination in good yield. Di-exo-methylenecyclobutane is also successfully applied to construct a bicyclo[5.2.0]nonenone skeleton by the reaction with 2-oxyallyl cation.
Methylthio- and methoxy-substituted allenylmethylsilanes, a kind of allylsilanes, undergo the ene-type reaction, not the usual allylsilane-type reaction accompanying by desilylation, with carbonyl and azo compounds mediated by a Lewis acid. The corresponding 1-silyl-substituted functionalized 1,3-dienes are obtained in good yields.