15879-41-1Relevant academic research and scientific papers
Re2O7-catalyzed reaction of hemiacetals and aldehydes with O-, S-, and C-nucleophiles
Sittiwong, Wantanee,Richardson, Michael W.,Schiaffo, Charles E.,Fisher, Thomas J.,Dussault, Patrick H.
, p. 1526 - 1532 (2013)
Re(VII) oxides catalyze the acetalization, monoperoxyacetalization, monothioacetalization and allylation of hemiacetals. The reactions, which take place under mild conditions and at low catalyst loadings, can be conducted using hemiacetals, the corresponding O-silyl ethers, and, in some cases, the acetal dimers. Aldehydes react under similar conditions to furnish good yields of dithioacetals. Reactions of hemiacetals with nitrogen nucleophiles are unsuccessful. 1,2-Dioxolan-3-ols (peroxyhemiacetals) undergo Re(VII)-promoted etherification but not allylation. Hydroperoxyacetals (1-alkoxyhydroperoxides) undergo selective exchange of the alkoxide group in the presence of either Re2O7 or a Bronsted acid.
Radical-transfer hydroamination of olefins with N-aminated dihydropyridines
Chou, Chih-Ming,Guin, Joyram,Mueck-Lichtenfeld, Christian,Grimme, Stefan,Studer, Armido
, p. 1197 - 1209 (2011/12/15)
An efficient synthesis of N-phthalimidyl, benzamidyl, acetamidyl, carbamoyl, and ureayl derivatives of dihydropyridines and the application of these reagents as precursors for N-centered radicals are presented. These aminated dihydropyridines could be used in radical-transfer hydroamination reactions of various electron-rich as well as nonactivated olefins in the presence of thiols as polarity-reversal catalysts. These reactions worked without the aid of any transition metal. Steric and electronic effects exerted by the N-substitutents of the N-centered radicals are discussed. In contrast to most metal-catalyzed processes, the radical hydroamination delivered the opposite regioisomer with excellent anti-Markovnikov selectivity. Hydroamination products were obtained as protected amines that are readily isolated. Festival of amination: We have presented an efficient synthesis of N-phthalimidyl, benzamidyl, acetamidyl, carbamoyl, and ureayl derivatives of dihydropyridines and the application of these reagents as precursors for N-centered radicals (see scheme). These aminated dihydropyridines can be used in radical-transfer hydroamination reactions.
Lewis acid-catalyzed ring-opening reactions of semicyclic N,O-acetals possessing an exocyclic nitrogen atom: Mechanistic aspect and application to piperidine alkaloid synthesis
Sugiura,Hagio,Hirabayashi,Kobayashi
, p. 12510 - 12517 (2007/10/03)
Ring-opening reactions of semicyclic N,O-acetals possessing an exocyclic nitrogen atom with silicon-based nucleophiles (silyl enol ethers, ketene silyl acetals, allylic silanes, and trimethylsilyl cyanide) were systematically studied for the first time. I
