Tin(IV) triflimidate-catalyzed cyclization of epoxy esters to functionalized δ-hydroxy-γ-lactones
摘要:
In the presence of 5 mol % of tin(IV) triflimidate, a cyclization reaction of epoxyesters to delta-hydroxy-gamma-lactones proceeding in 46-98% yields without additives, ligands, or co-catalysts was observed. The cyclization to five-membered rings is greatly favored compared to the possible six-membered rings formation and is probably under the control of a Thorpe-Ingold type effect. (C) 2009 Elsevier Ltd. All rights reserved.
Tin-free radical alkylation of ketones viaN-silyloxy enamines
作者:Hyun-Ji Song、Che Jo Lim、Sunggi Lee、Sunggak Kim
DOI:10.1039/b606295d
日期:——
The radical alkylation of ketones is achieved by their conversion into corresponding N-silyloxy enamines, followed by a radical reaction with alkyl halides bearing electron-withdrawing groups.
Preparation and Reactivities of (η<sup>3</sup>-1- and 2-Trimethylsiloxyallyl)Fe(CO)<sub>2</sub>NO Complexes. Intermediates Functioning as Equivalents of β- and α-Acyl Carbocations and Acyl Carbanions
作者:Keiji Itoh、Saburo Nakanishi、Yoshio Otsuji
DOI:10.1246/bcsj.64.2965
日期:1991.10
(η3-1- and 2-Trimethylsiloxyallyl)Fe(CO)2NO complexes were prepared by the reaction of the corresponding siloxyallylic halides with Bu4N[Fe(CO)3NO]. These complexes reacted with both of carbon nucleophiles and carbon electrophiles preferentially at the less hindered sites of the allylic ligands. In these reactions, (η3-1-trimethylsiloxyallyl)Fe(CO)2NO complexes served as synthetically equivalent synthons
A novel synthesis of alkylbismuthonium salts and their reaction with some nucleophiles. First X-ray structural analysis of a stabilized alkylbismuthonium tetrafluoroborate
作者:Yoshihiro Matano、Nagao Azuma、Hitomi Suzuki
DOI:10.1016/s0040-4039(00)61358-8
日期:1993.1
Treatment of triarylbismuth difluorides 1 with silyl enol ethers 2 in the presence of BF3·OEt2 gives (2-oxoalkyl)triarylbismuthonium tetrafluoroborates 3 as a stable crystalline solid, the bismuth centre of which has been found by X-ray analysis to possess a tetragonal geometry. The 2-oxoalkyl moiety of compound 3 couples with enolates and thiolates to afford the corresponding triketones 4 and α-thioketones