3-Silyloxytetrahydrofurans via sulfoxonium ylide reactions with α-silyloxyepoxides
摘要:
alpha-Silyloxyepoxides were found to undergo sulfoxonium ylide induced ring-opening, followed by silyl-migration and intramolecular S(N)2 reaction, resulting in 3-silyloxytetrahydrofurans. Studies on the scope and utility of this transformation are described. (C) 2007 Elsevier Ltd. All rights reserved.
Oxidation of Olefins into α-Phenylseleno Carbonyl Compounds. Highly Regioselective<i>anti</i>-Markownikoff Type Oxidation of Allylic Alcohol Derivatives
作者:Makoto Shimizu、Ryo Takeda、Isao Kuwajima
DOI:10.1246/bcsj.54.3510
日期:1981.11
(C6H5Se)2–(C6H5SeO)2O system, oxoselenenylation reactions of C=C bonds have been examined with allylic and homoallylic alcohol derivatives, and substituted cyclohexenes, and allyl t-butyldimethylsilyl ethers are found to undergo regioselective conversion into β-siloxy α-phenylseleno carbonylcompounds in high yields.
The combo pack: Copper‐catalyzed trifluoromethylation of alkenes bearing an allylic proton combined with CCbondformation affords the title compounds in good to high yields (see scheme). The reactions are faster than allylic trifluoromethylation, especially in 1,4‐dioxane. A unique 1,6‐oxytrifluoromethylation occurred instead of an anticipated seven‐membered ring forming carbotrifluoromethylation
The influence of α-coordinating groups of aldehydes on <i>E</i>/<i>Z</i>-selectivity and the use of quaternary ammonium counter ions for enhanced <i>E</i>-selectivity in the Julia–Kocienski reaction
Modified reaction conditions for improved E-selectivity of olefins in the Julia–Kocienski reaction of aldehydes having α-coordinating substituents are demonstrated. The chelating groups in aldehydes are expected to stabilize the syn-transition state with metal ions, whereas the weakly coordinating quaternary ammonium ions are devoid of all possible chelating interactions to enhance E-selectivity. A