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
The palladium(0)-catalyzed carbonylations, in acetic acid as a necessary solvent, of 2,7-octadienyl acetate and homologues via pi-allylpalladium species were preceded by their intramolecular oelfin insertion to form mixtures of cis/trans-2-vinylcyclopentylacetyl- and cis/trans-cyclohexylacetylpalladium intermediates, which undergo further the intramolecular (5-exo) Heck reaction to give bicyclo-[3.3.0] and [4.3.0] skeletons, respectively, except for one case affording trans-2-vinylcyclopentylacetic acid as a major product.