Efficient approach to 1,2-diazepines via formal diazomethylene insertion into the C-C bond of cyclobutenones.
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 4π-ring opening of cyclobutene followed by an 8π-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.
Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
Kenji
K
Sugimoto
Rie
R
Hayashi
Hideo
H
Nemoto
Naoki
N
Toyooka
Yuji
Y
Matsuya
D001381:Azepines / Q000138:chemical synthesis* / Q000737:chemistry; D003503:Cyclobutanes / Q000737:chemistry*; D003978:Diazomethane / Q000031:analogs & derivatives / Q000737:chemistry*; D015394:Molecular Structure
D001381:Azepines; D003503:Cyclobutanes; C553737:cyclobutenone; D003978:Diazomethane