Palladium-catalyzed cascade ring expansion reaction of 1-(3-methoxycarbonyloxy-1-propynyl)cyclobutanols with phenols
作者:Masahiro Yoshida、Hideo Nemoto、Masataka Ihara
DOI:10.1016/s0040-4039(99)01749-9
日期:1999.12
opynyl)cyclobutanols to cyclo-pentanones on treatment with phenol derivatives is described. This process can be visualized to proceed via nucleophilicattack to allenyl palladium species by phenol, followed by ring expansion reaction of π-allylpalladiumcomplex to form the corresponding cyclopentanone.
A Novel Methodology for the Synthesis of Cyclic Carbonates Based on the Palladium-Catalyzed Cascade Reaction of 4-Methoxycarbonyloxy-2-butyn-1-ols with Phenols, Involving a Novel Carbon Dioxide Elimination-Fixation Process
A palladium-catalyzed CO2-recycling reaction has been developed. Reaction of 4-methoxycarbonyloxy-2-butyn-1-ols with phenols, carried out in the presence of a palladium catalyst, produces phenoxy-substituted cyclic carbonates by way of a pathway involving a CO2 elimination-fixation. A variety of propargylic alcohols and phenols participate in these reactions which yield cyclic carbonates with high efficiencies. Stereoselective construction of trans-cyclic carbonates is achieved by using nonsymmetric substrates. Highly enantioselective reactions occur when (S)-BINAP is used as a ligand. Reaction of 4-phenoxycarbonyloxy2-butyn-1-ol in the presence of the palladium catalyst yields the corresponding cyclic carbonates via a three-component decomposition-reconstruction process.
Au(I)-catalyzed tandem [3,3]-sigmatropic rearrangement–cycloisomerization cascade as a route to spirocyclic furans
作者:Hyun-Suk Yeom、Suk-Jae Yoon、Seunghoon Shin
DOI:10.1016/j.tetlet.2007.05.067
日期:2007.7
Gold-catalyzed reaction of 1-(3-hydroxypropynyl)cycloalkanol derivatives was studied. The reaction profile was highly dependent on the ring size, migrating group, as well as reaction conditions. An efficient route to spirocyclic furans via tandem (3,3]-sigmatropic rearrangement-cycloisomerization is reported. (c) 2007 Elsevier Ltd. All rights reserved.
Palladium-catalysed cascade ring expansion reaction of cyclobutanols that have a propargylic moiety with nucleophiles
Cascade ring rearrangement of four-membered ring systems containing various propargylic components by a palladium catalyst is described. The reactions of cyclobutanols that have a propargylic carbonate moiety with phenols as nucleophiles produce phenoxy-induced cyclopentanones in high yields. The reactions proceed in a regio- and diastereoselective manner to afford the substituted cyclopentanones with