Hiyama couplings

Palladium-catalyzed cross-coupling between vinylsilane 119 and 3-iodoqui-noline 91 then assembled 92 in 83% yield. 

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In Scheme 10, HMG-CoA reductase inhibitor 92 was synthesized via a Suzuki coupling approach. Hiyama s group also carried out a Hiyama coupling to make the same compound (93TL8263). Vinylsilane 119 was prepared by platinum-catalyzed reaction from terminal alkyne 89. 

Scheme 6.39 Hiyama coupling between activated aryl bromides/chlorides and phenyl/vinyl-trimethoxysilane...

Scheme 6.29 Hiyama couplings of of bis(catechol) silicates with aryl bromides.

The Hiyama coupling of aryltrimethoxysilane 47 and 3-bromopyridine assembled arylpyridine 48 with the aid of TBAF [57], In contrast to chlorosilanes, which are susceptible to hydrolysis, aryltrialkoxysilanes are not. 

The Hiyama coupling offers a practical alternative when selectivity and/or availability of other reagents are problematic. Hiyama et al. coupled alkyltrifluorosilane 74 with 2-bromofuran 73 to give the corresponding cross-coupled product 75 in moderate yield in the presence of catalytic Pd(Ph3P)4 and 3 equivalents of TBAF [65]. In this case, more than one equivalent of fluoride ion was needed to form a pentacoordinated silicate. On the other hand, alkyltrifluorosilane 74 was prepared by hydrosilylation of the corresponding terminal olefin with trichlorosilane followed by fluorination with C11F2. This method provides a facile protocol for the synthesis of alkyl-substituted aromatic compounds. 

For catalytic enantioselective carbonyl allylation and crotylation via NozaM-Hiyama coupling, see [248-257]. 

For recent reviews of catalytic Nozaki-Hiyama coupling, see [258-261]. 

Reaction with Organosilicon Reagents (Hiyama Coupling) 668... 

The carbonylative cross-coupling was successfully extended to organofluorosilanes by Hiyama. TVN -Dimethyl-2-imidazolidmone was found to be the most effective solvent for the carbonylative Hiyama-coupling, which was run in the presence of potassium fluoride. 3-Iodoquinoline, for example, reacted smoothly with 2-(ethyldifluorosilyl)-thiophene (7.68.) under an ambient pressure of carbon monoxide to give the desired ketone in 78% isolated yield.89... 

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