Development of palladium(II) catalyzed reactions for macrocyclization

ORGN 106

Juan M. Fernandez, almestar@chem.ucla.edu and Craig A. Merlic, merlic@chem.ucla.edu. Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles Young Drive, Los Angeles, CA 90095
An efficient and straightforward route for unsymmetrical macrocyclization producing E,E-diene macrocycles was developed using pinacol vinylboronate esters and palladium(II) catalysis. When vinylboronates were treated with a catalytic amount of PdCl2(PPh3)2 and chloroacetone as the oxidant in high dilution in methanol, formation of E,E-dienes was successfully achieved. For example, 14-, 15- and 16-membered E,E-diene macrocycles were obtained in good yields and as single geometrical isomers. Overall, this protocol is synthetically more efficient than a typical palladium(0) catalyzed coupling of substrates containing both electrophilic and nucleophilic end groups.

 

Process R&D, Physical Organic Chemistry, Heterocycles, Aromatics, Metal-Mediated Reactions
8:00 PM-10:00 PM, Sunday, March 25, 2007 Hyatt Regency Chicago -- Riverside Center, Poster

Division of Organic Chemistry

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007