Pd Nanoparticle-Catalyzed Stereospecific Mizoroki-Heck Arylation of cis-1,2-Disilylarylethylenes
Georgios Kyriakakis1, Marios Kidonakis1, Anastasia Louka1
1Department of Chemistry, University of Crete, Voutes, 71003 Heraklion, Greece.
Abstract:
In the presence of catalytic amounts of Pd nanoparticles, generated from Pd2dba3/Ag(I), cis-1,2-ditrimethylsilylarylethylenes undergo with aryl iodides a stereospecific Mizoroki-Heck arylation leading to trans-ditrimethylsilyldiarylethylenes. This chemoselectivity is in contrast to that of their trimethylgermyl analogues, which are arylated at the position of the C-Ge bonds. trans-1,2-Ditrimethylsilylarylethylenes are completely unreactive under the standard reaction conditions. The reaction tolerates the presence of boryl, silyl, or bromine substituents on the aryl iodides. From a mechanistic point of view, the process involves syn-arylpalladation followed by syn-dehydropalladation.
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