Facile synthesis of alkyl β-benzyloxyaminocarboxyolates related to monocyclic β-lactams.
作者:Kiyoshi Ikeda、Kazuo Achiwa、Minoru Sekiya
DOI:10.1016/s0040-4039(00)86233-4
日期:1983.1
N-Benzyloxyimines have been shown to react with ketene silyl acetals in the presence of trimethylsilyl triflate catalyst to give alkyl β-benzyloxyaminocarboxylates. Conversion of them to β-lactams has been exemplified.
Organocatalytic Nucleophilic Substitution Reaction of <i>gem</i>-Difluoroalkenes with Ketene Silyl Acetals
作者:Azusa Kondoh、Kazumi Koda、Masahiro Terada
DOI:10.1021/acs.orglett.9b00566
日期:2019.4.5
An organocatalytic nucleophilic substitution reaction of gem-difluoroalkenes with ketene silyl acetals was developed. Phosphazene P4-tBu effectively catalyzed the reaction under mild conditions to provide monofluoroalkenes possessing an alkoxycarbonylmethyl group in high yields with high Z selectivities.
开发了宝石-二氟烯烃与乙烯酮甲硅烷基缩醛的有机催化亲核取代反应。磷腈P4- t Bu在温和条件下有效催化了该反应,以高收率和高Z选择性提供了具有烷氧羰基甲基的一氟烯烃。
A new route to 4-unsubstituted .BETA.-lactams through ureidomethylation of ketene silyl acetals.
作者:KIYOSHI IKEDA、YOSHIYASU TERAO、MINORU SEKIYA
DOI:10.1248/cpb.29.1747
日期:——
α-Ureidomethylated carboxylates were obtained by the reaction of ketene silyl acetals with benzyl N-(chloromethyl) carbamates in the presence of titanium tetrachloride. Successive hydrogenolysis over palladium-on-charcoal followed by treatment with lithium diisopropylamide gave β-lactams.