Microwave- and photoirradiation-induced staudinger reactions of cyclic imines and ketenes generated from alpha-diazoketones. A further investigation into the stereochemical process.
Reactions of ketenes generated from alpha-diazoketones with a series of acyclic and cyclic imines were investigated under both microwave and photoirradiation conditions. The results indicate that the zwitterionic azabutadiene-type intermediates yielded from imines and ketenes undergo a conrotatory ring closure exclusively to produce beta-lactams. It is notable that no Woodward-Hoffmann product was found under the ultraviolet irradiation. The photoirradiation-induced Staudinger reaction shows a different stereoselectivity from the electrocyclic reaction of substituted 1,3-butadiene.
Liang
Yong
Y
Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.
Jiao
Lei
L
Zhang
Shiwei
S
Xu
Jiaxi
J
D001391:Azo Compounds / Q000737:chemistry*; D002384:Catalysis; D007097:Imines / Q000737:chemistry* / Q000528:radiation effects; D007659:Ketones / Q000737:chemistry* / Q000528:radiation effects; D008872:Microwaves; D013237:Stereoisomerism; D047090:beta-Lactams / Q000138:chemical synthesis*
D001391:Azo Compounds; D007097:Imines; D007659:Ketones; D047090:beta-Lactams