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.
The influence of remote heteroatom substituents on the stereoselectivity of cyclopentene ozonolysis
作者:William H. Bunnelle、Terry A. Isbell
DOI:10.1021/jo00028a059
日期:1992.1
The stereoselectivity for ozonide formation from cyclopentenes with allylic heteroatom substituents has been examined. Silyl ethers give high selectivity in favor of the exo-substituted ozonide, while esters of 2-cyclopentenol form ozonide mixtures with little stereoselection. Trapping experiments establish that fragmentation of the primary ozonides is highly regioselective to give only one of the isomeric omega-oxo carbonyl oxide intermediates and that the variation in final ozonide stereochemistry results from differing interactions between the remote substituent groups and the carbonyl oxide system during cyclization of this intermediate. The effect of substituent and solvent on ozonide stereochemistry suggests a dominant role for electrostatic repulsion between carbonyl oxide and the heteroatom substituent during intramolecular cycloaddition. A chair-like transition state is proposed for this process and is in accord with the increase in exo selectivity for derivatives of 2-methyl-2-cyclopentenol.
A new method for converting oxiranes to allylic alcohols by an organosilicon reagent
作者:S. Murata、M. Suzuki、R. Noyori
DOI:10.1021/ja00504a045
日期:1979.5
NOYORI, R.;MURATA, S.;SUZUKI, M., TETRAHEDRON, 1981, 37, N 23, 3899-3910