%0 Journal Article %T Palladium-catalyzed double cross-coupling of E-vinylic dibromides with PhZnCl and the synthesis of tamoxifen %A Pilli %A Ronaldo A. %A Robello %A Lu¨ªs Gustavo %J Journal of the Brazilian Chemical Society %D 2004 %I Sociedade Brasileira de Qu¨ªmica, SBQ %R 10.1590/S0103-50532004000600023 %X (e)-1,2-vinylic dibromides 11a-f were stereoselectively prepared via bromination of acetylenic compounds with pyridinium tribromide in meoh/ccl4 at low temperature and double cross-coupled with phzncl under pd(0) catalysis (negishi protocol) to afford tri- and tetrasubstituted olefins 14a-e. tamoxifen, a selective estrogen receptor modulator clinically prescribed in breast cancer therapy, was prepared in 7 steps and 30% overall yield from 4-iodophenol (3) as a 2.3:1 mixture of (z)- and (e)-isomers. %K (e)-1 %K 2-vinylic dibromides %K double cross-coupling %K palladium catalysis %K tri- and tetrasubstituted olefins %K tamoxifen. %U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0103-50532004000600023&lng=en&nrm=iso&tlng=en