Efficient Approach to 1,2-Diazepines via Formal Diazomethylene Insertion into the C–C bond of Cyclobutenones
作者:Kenji Sugimoto、Rie Hayashi、Hideo Nemoto、Naoki Toyooka、Yuji Matsuya
DOI:10.1021/ol301474g
日期:2012.7.6
Efficient monocyclic 1,2-diazepine formation via a tandem electrocyclization reaction of cyclobutenones with lithiodiazoacetate is demonstrated. The reaction proceeds through an oxy anion-accelerated 4 pi-ring opening of cyclobutene followed by an 8 pi-ring closure of the resultant oxy anion-substituted diazo-diene under mild conditions to furnish a 1,2-diazepine via formal diazomethylene insertion into the C-C bond of cyclobutenone.