Thermolysis of O,O-t-butyl and O-isopropenyl percarbonate in cyclohexane involves free-radical acetonylation of solvent. Free radicals derived from solvent add to the percarbonate double bond and after a double β-scission reaction, cyclohexylacetone carbon dioxide and t-butoxy radicals are formed. Abstracting H atoms from the solvent, t-butoxy radicals regenerate free radicals from solvent, and the
Potassium permanganate-mediated radical reactions: chemoselective addition of acetone to olefins
作者:Ursula Linker、Berthold Kersten、Torsten Linker
DOI:10.1016/0040-4020(95)00563-n
日期:1995.1
efficient protocol for the radicaladdition of acetone (1) to olefins 2a-d, mediated by potassium permanganate, has been developed. The in situ generation of manganese(III) allows the chemoselective synthesis of saturated C-C bond formation products 4a-d in 39–58% yield. Furthermore, the required amount of manganese is reduced drastically in account of the catalytic reaction cycle.
Importance of the aromatic ring in adrenergic amines. 7. Comparison of the stereoselectivity of norepinephrine N-methyltransferase for aromatics. Nonaromatic substrates and inhibitors
作者:Michael F. Rafferty、David S. Wilson、James A. Monn、Polina Krass、Ronald T. Borchardt、Gary L. Grunewald
DOI:10.1021/jm00352a020
日期:1982.10
the lipophilicity of the nonaromatic ethanolamine analogues was increased, a loss in both stereoselectivity and substrate activity occurred. The results presented here are consistent with an aromaticring binding site that is part of, or bordered by, a large hydrophobic area. The larger, more hydrophobicnonaromaticphenylethanolamine derivatives are drawn into the hydrophobic area, which reduces side-chain