A new synthetic route was developed via the nucleophilic addition of lithium alkynylide to 1-arylsulfonyl cyclopropanol 1 to afford 1-alkynyl cyclopropanol, which then reacted with aryl iodide to construct trisubstituted cross-conjugated dienones through a palladium-catalyzed process, where the key steps included the regioselective carbopalladation of arylpalladium(II) intermediate across the triple
Gold(I)-Catalyzed Ring Expansion of Cyclopropanols and Cyclobutanols
作者:Jordan P. Markham、Steven T. Staben、F. Dean Toste
DOI:10.1021/ja052831g
日期:2005.7.13
The reaction tolerates terminal alkynes as well as alkyl, aryl, and halo-substitution at the acetylenic position and stereoselectively provides a single olefin isomer. The gold(I)-catalyzed rearrangement is stereospecific with regard to substituents on the ring, thus providing a practical method for the stereoselective synthesis of highly substituted cyclopentanones from cyclopropanols. The reaction stereoselectively
A convenient new method was developed to prepare two types of vinyl cyclopropane derivatives through gold-catalyzed cyclization of 1-alkynyl cyclopropyl tert-butyl carbonates 2. Different from the previous reported 5-exo-dig route, the 6-endo-dig addition is the preferred pathway to provide six-membered cyclized carbonates. Two factors, including stereoelectronic effect and steric effect might affect
Gold(I)‐Catalyzed Ring Expansion of Alkynylcyclopropyl Allyl Ethers to Construct Tetrasubstituted Methylenecyclobutanones: A Mechanistic Investigation about the Character of Catalytic Amount of Water
mechanism has been proposed on the basis of deuterium and 18O‐labeling experiments, Mass spectroscopic analysis, 1H and 13Cnuclearmagneticresonance (NMR) spectroscopic tracking and density functional theory (DFT) calculations. The further transformation of these methylenecyclobutanones into polycyclic skeleton has been realized by a practical three‐step synthetic procedure. Several other transformations