Stereo defined 2-arylethenyldimethylphenylsilanes, 1, do react with aryl iodides, 6, containing an electron-donating substituent as well as with 2-thienyl iodide, 7, in the presence of a catalytic amount of a palladium complex and a molar excess of a 1 M THF solution of dry tetrabutylammonium fluoride (TBAF), to give (E)-1,2-diarylethenes, (E)-9, stereoselectively. Evidence has been obtained that the formation of compounds (E)-9 occurs primarily through a process which involves protodesilylation of compounds 1 by means of TBAF, followed by a Heck-type reaction between aryl iodides and arylethenes, 10. 1-alkynyldimethyl-phenylsilanes, 2, also do react with aryl iodides 6, in the presence of a catalytic quantity of (eta-3-C3H5PdCl)2 and a molar excess of a THF solution of dry TBAF, to afford 1,2-diarylethynes, 14, in modest yields.
Palladium-mediated reaction between aryl iodides and stereodefined (2-arylethenyl)dimethylphenylsilanes or (2-arylethynyl)dimethylphenylsilanes in the presence of a fluoride ion source
ROSSI, RENZO;CARPITA, ADRIANO;
1992-01-01
Abstract
Stereo defined 2-arylethenyldimethylphenylsilanes, 1, do react with aryl iodides, 6, containing an electron-donating substituent as well as with 2-thienyl iodide, 7, in the presence of a catalytic amount of a palladium complex and a molar excess of a 1 M THF solution of dry tetrabutylammonium fluoride (TBAF), to give (E)-1,2-diarylethenes, (E)-9, stereoselectively. Evidence has been obtained that the formation of compounds (E)-9 occurs primarily through a process which involves protodesilylation of compounds 1 by means of TBAF, followed by a Heck-type reaction between aryl iodides and arylethenes, 10. 1-alkynyldimethyl-phenylsilanes, 2, also do react with aryl iodides 6, in the presence of a catalytic quantity of (eta-3-C3H5PdCl)2 and a molar excess of a THF solution of dry TBAF, to afford 1,2-diarylethynes, 14, in modest yields.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
