Mechanism of the Au(I)-catalyzed enyne cycloisomerization reaction

ORGN 314

Paul Ha-Yeon Cheong, hycheong@chem.ucla.edu1, K. N. Houk, houk@chem.ucla.edu1, and F. Dean Toste, fdtoste@berkeley.edu2. (1) Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, East, Los Angeles, CA 90095-1569, (2) Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460
Mechanistic investigations of recent advances in Au(I)-catalyzed enyne cycloisomerizations have been completed by density functional calculations. Three general mechanisms were originally proposed for this transformation - an ene reaction catalyzed by Au(I), an ene reaction of an alkyne gold exchange product, and a pathway involving the formation of a Au(III) metallocycle intermediate. The calculation results have clarified the mechanism of this reaction, and experimental observations corroborate the calculated mechanism. Unique substrate reactivity differences regarding the terminal substituent of the alkyne have been discovered, and corresponding computational results that explain these differences will be presented.

 

Metal-Mediated Reactions and Syntheses
1:00 PM-5:00 PM, Monday, 11 September 2006 Moscone Center -- Room 133, Oral

Division of Organic Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006