Gold(I)-catalyzed ring expansion of cyclopropanols and cyclobutanols.
The rearrangement of 1-alkynyl cyclobutanols and cyclopropanols to alkylidene cycloalkanones catalyzed by cationic triarylphosphine gold(I) complexes is described. 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 provides a single olefin isomer and is stereospecific with regard to substituents on the ring via sequential gold(I)-catalyzed ring expansion reactions.
Department of Chemistry, University of California, Berkeley, California 94720, USA.
Jordan P
JP
Markham
Steven T
ST
Staben
F Dean
FD
Toste
D000440:Butanols / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D004988:Ethers, Cyclic / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure
D000440:Butanols; D004988:Ethers, Cyclic; D008024:Ligands; C043657:cyclopropanol; D006046:Gold