Single-isomer tetrasubstituted olefins from regioselective and stereospecific palladium-catalyzed coupling of beta-chloro-alpha-iodo-alpha,beta-unsaturated esters.
The efficient regioselective and stereospecific synthesis of tetrasubstituted olefins using a mild and convenient method is disclosed. 2-Alkynyl esters are selectively converted to E-beta-chloro-alpha-iodo-alpha,beta-unsaturated esters by exposure to Bu4NI in refluxing dichloroethane. These products are produced cleanly, regio- and stereoselectively, and in high yields. Single-isomer tetrasubstituted olefins bearing four different carbon substituents are then synthesized by sequential palladium-catalyzed coupling reactions. Selectivity results from reactivity differences in the intermediate substrates.
Lemay
Alison B
AB
Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, Canada K1N 6N5.
Vulic
Katarina S
KS
Ogilvie
William W
WW
D000475:Alkenes / Q000138:chemical synthesis*; D002384:Catalysis; D004952:Esters; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry; D006847:Hydrocarbons, Iodinated / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D013237:Stereoisomerism
D000475:Alkenes; D004952:Esters; D006843:Hydrocarbons, Chlorinated; D006847:Hydrocarbons, Iodinated; D010165:Palladium