Gold-Catalyzed Rearrangement of (Silylcyclopropenyl)methyl Ethers into (Silylmethylene)cyclopropanes

Article abstract of DOI:10.1055/s-0035-1561486

Methoxymethyl ethers derived from 2-(dimethylphenylsilyl)cycloprop-1-enyl carbinols undergo gold-catalyzed rearrangement leading to [(Z)-(dimethylphenylsilyl)methylene]cyclopropanes in moderate to high yields with methyl formate as a byproduct. This transformation proceeds by initial regioselective ring opening of the three-membered ring leading to an α-silyl vinyl gold carbenoid. This latter organogold species evolves by 1,5-hydride transfer, which triggers subsequent rearrangement involving loss of methyl formate, 2π-electrocyclization of the resulting allylic cation, and elimination of the metal to regenerate the catalyst.