Furanosides and furanones bearing acrylate sidechains via palladium-mediated cyclizations of γ-Oxoallenes
摘要:
Treatment of 4,5-hexadienal with catalytic palladium(II) chloride and excess copper(II) chloride, methanol and carbon monoxide in the presence of an acid and a water scavenger resulted in a net acetalization-cyclization-methoxycarbonylation to form a novel methyl furanoside bearing a methyl acrylate sidechain. Treatment of 4,5-hexadienoic acid under the same conditions yields the corresponding furanone, and 3-(tert-butylidimethylsilyloxy)-4,5-hexadienal yields a methyl beta-3'-(tert-butyldimethylsilyloxy)-2'-deoxyribofuranoside bearing the acrylate sidechain, with high stereoselectivity. This methodology provides access to sidechain-branched ribofuranoside compounds.
A palladium-catalyzed cyclization-carbonylation-coupling reaction between aryl halides and γ-Hydroxyallenes to form aryl (tetrahydrofuran-2-yl)vinyl ketones
作者:Robert D. Walkup、Lufeng Guan、Young Soo Kim、Sang Woong Kim
DOI:10.1016/0040-4039(95)00666-z
日期:1995.5
γ-Hydroxyallenes undergo cyclization-carbonylation-coupling with aryl (and one alkenyl) halides in the presence of catalytic Pd(PPh3)4, base, and CO to form the title ketones in good yields. The reaction was temperature dependent: at 80 °C, the CO insertion did not readily occur, while at 55–60 °C the ketone products predominated. Yields for the Pd(0)-catalyzed cyclization-coupling reaction (without
Palladium(0)-Catalyzed Coupling Cyclization of Functionalized Allenes with Hypervalent Iodonium Salts
作者:Suk-Ku Kang、Tae-Gon Baik、Alexander N. Kulak
DOI:10.1055/s-1999-2613
日期:1999.3
The palladium(0)-catalyzed coupling reaction of allenic alcohols, amines, acids with hypervalent iodonium salts afforded the cyclized heterocyclic tetrahydrofurans, tetrahydropyrans, pyrrolidines, piperidines, or lactones under mild conditions.
Preparation of 2-(Tetrahydrofuran-2′-YL)-l,4-Pentadienes From γ-Allenyl Alcohols via Oxymercuration Followed by Palladium(II)-Medlated all Ylation
作者:Robert D. Walkup、Lufeng Guan
DOI:10.1080/00397919208019290
日期:1992.4
Abstract Intramolecular oxymercurations of γ-hydroxy- or γ-silyloxyallenes yielded α-(tetrahydrofuran-2-yl)vinylmercury intermediates which underwent coupling with allylic halides in the presence of palladium(II) chloride. The yields of the resulting 2-(tetrahydrofuran-2′-yl)-1,4-pentadienes diminished when either the vinylmercury compound or the allylic halide was substituted.
Ragonnet,B. et al., Bulletin de la Societe Chimique de France, 1973, p. 3119 - 3121
作者:Ragonnet,B. et al.
DOI:——
日期:——
Access to -2,5-disubstituted iodovinyltetrahydrofurans via the cyclization of γ-silyloxyallenes using n-iodosuccinimide
作者:Robert D Walkup、Lufeng Guan、Sang Woong Kim、Young Soo Kim
DOI:10.1016/0040-4039(92)88075-g
日期:1992.7
Treatment of gamma-(tert-butyldimethylsiloxy)- or gamma-(trimethylsiloxy)allenes bearing various groups at the ether carbon with N-iodosuccinimide resulted in the formation of iodocyclization products, 1-iodo-1-(tetrahydrofuran-2'-yl)ethenes, in good yields and with high selectivity for the cis diastereomer.