Search

Deuterium-labeling experiments were performed for the Fe(PMe3)4-catalyzed C–H/olefin coupling using a deuterium-labeled aromatic ketone with various alkenes. While the reactions with a variety of alkenes provided the linear alkylation products formed via 1,2-insertion of alkene into an Fe–H bond, the reversible 2,1-insertion proceeded during the reaction highly depends on the choice of the alkene. No H/D scrambling resulting from 2,1-insertion/β-elimination was detected for the reactions with a vinylsilane and N-vinylcarbazole, but the reactions­ with styrenes are considered to involve rapid 2,1-insertion/ β-elimination processes to cause significant levels of H/D scrambling.

We herein disclose the first Ni-catalyzed Hiyama coupling of aryl halides with vinylsilanes. This protocol uses cheap, nontoxic, and stable vinyltrimethoxysilane as the vinyl donor, proceeds under mild and ligand-free conditions, furnishing a diverse variety of styrene derivatives in high yields with excellent functional group compatibility.

Vinylsilanes are versatile and efficient nucleophiles in cross-coupling reactions. Herein is described the use of tetrabutylammonium bifluoride as a mild, cheap and scalable activating agent in several copper-catalyzed vinylsilane cross-couplings.

Conversion of α-amino aldehydes into protected amino-hydroxy-methyl stereotriads carrying an E-trisubstituted vinyl iodide unit was effected by means of a three-step protocol: a Marshall reaction of the α-amino aldehyde with a chiral propargylic mesylate, a silylcupration of the corresponding homopropargylic alcohol and an iododesilylation reaction of the resulting vinylsilane. This sequence delivered the expected compounds as their oxazolidinone derivatives, providing a convenient diastereoselective access to useful building blocks for polypropionate synthesis and polyketide derivatives.

1,3-Diene-2,3-diyl diesters are synthesized by rhodium-catalyzed homocoupling of (1-acyloxyvinyl)silanes. Double transmetalation between vinylsilane and rhodium intermediate in a single catalytic cycle is the key in this reaction. From the homocoupling products, symmetrical α-diketone and its monoacetal are easily synthesized.

Silyl ethers can be produced from alcohols and vinyl-silanes under a rhodium(I) catalyst. The reaction is believed to proceed through an O-H bond cleavage of alcohol by rhodium(I) complex and a subsequent hydride insertion into vinylsilane followed by β-silyl elimination of the resulting β-silylethyl rhodium(III) complex.

β-Amino alcohols possessing a vinylsilane functionality were transformed into bicyclic derivatives via a diastereoselective 5-exo-trig radical cyclization. Straightforward transformation led to enantiopure proline derivatives.