Palladium-promoted reaction Hiyama

TBAF can promote hiaryl formation from triaflyl(aryl)silanes and a wide variety of aryl halide suhstrates. For example, chlorobenzenes undergo smooth cross-couphng with triallyl(aryl)silanes to give biaryls in good to excellent yields (eq 31). Surprisingly, an appreciable amount of added water is required to achieve high yields however, the role of added water is not yet clear.In a recent variant of the Hiyama reaction, TBAF and palladium-coated nickel nanoclusters were employed to prepare biaryl compounds from aryl bromides and phenyltrimethoxysilane. ... 

The use of alkenylsilyl ethers in palladium-catalyzed cross-coupHng reactions has long been known. In fact, only a year after Hiyama s landmark report on the TBAF-promoted coupling reactions of vinyltrimethylsilane, Tamao and Ito capitahzed on the use of alkoxy-substituted silanes as viable components for such reactions (cf Scheme 7.4). The generahty of the silyl ether coupHng added a useful class of organosilicon substrates that are complementary to the fluorosilanes developed by Hiyama et al. These studies showed that other heteroatom-based... 

The palladium-catalyzed Hiyama reaction is a cross-coupling between aryl halides and silanes (Scheme 19.47) [65]. Silane derivatives are easily available. They are stable with a low toxicity. However, they exhibit a low reactivity, and the reactions must be performed at high temperatures. Reactions are promoted by fluoride ions [65]. 

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