Ring Opening of Oxiranes by Trimethylsilyl Trifluoromethanesulfonate
作者:Sizuaki Murata、Masaaki Suzuki、Ryoji Noyori
DOI:10.1246/bcsj.55.247
日期:1982.1
Trimethylsilyl trifluoromethanesulfonate promotes ringopening reactions of oxirane derivatives. The reaction course is highly affected by the structures and substitution pattern of the substrates. Tetra-, tri-, and 2,2-disubstituted oxiranes and simple cycloalkene oxides are converted to the corresponding allylic alcohol trimethylsilyl ethers. The overall transformation is interpreted in terms of
Trimethysilyl triflate in organic synthesis11Part 11 of this series. Part 10: S. Murata and R. Noyori, Tetrahedron Letters 2107 (1981).
作者:R. Noyori、S. Murata、M. Suzuki
DOI:10.1016/s0040-4020(01)93263-6
日期:——
Trimethylsilyl triflate is a powerful silylating agent for organic compounds and acts as a catalyst which accelerates a variety of nucleophilic reactions in aprotic media. The reactions proceed via one-center, electrophilic coordination of the silyl group to hetero functional groups and exhibit unique selectivities.
reactions of enol ethers (ROCC, R = alkyl, silyl) with zinc carbenoid reagents were found to give allylic ethers in several cases along with the expected cyclopropylethers. The ratio of these two products was highly dependent on the concentration of the reaction mixture. Thus, the selective formation of each product was conveniently attained by merely changing the amounts of the solvent used. Zinc iodide
Demystifying Cp<sub>2</sub>Ti(H)Cl and Its Enigmatic Role in the Reactions of Epoxides with Cp<sub>2</sub>TiCl
作者:Jonathan Gordon、Sven Hildebrandt、Kendra R. Dewese、Sven Klare、Andreas Gansäuer、T. V. RajanBabu、William A. Nugent
DOI:10.1021/acs.organomet.8b00793
日期:2018.12.24
2-epoxy-1-methylcyclohexane with Cp2TiCl as a model. Rapid evolution of hydrogen gas was demonstrated, indicating that Cp2Ti(H)Cl is indeed a thermally unstable molecule, which undergoes intermolecular reductive elimination of hydrogen under the reaction conditions. The stoichiometry of the reaction (Cp2TiCl:epoxide = 1:1) and the quantity of hydrogen produced (1 mol per 2 mol of epoxide) is consistent with this
An appropriate solvent to perform the original Simmons–Smith reaction was reinvestigated. Among available solvents, cyclopentyl methyl ether (CPME), a recently commercialized ethereal solvent, was found to be the best so far. Compared with Et2O under reflux – the commonest conditions – reaction completion in CPME at 50 °C was about 10 times faster. The product yields and selectivities were mostly identical