Epoxide Formation by Ring Closure of the Cinnamyloxy Radical
作者:Jérôme Amaudrut、Olaf Wiest
DOI:10.1021/ol005749t
日期:2000.5.1
oxiranyl benzyl radicals were generated by photolysis of alkyl 4-nitrobenzenesulfenates. The yet unprecedented epoxide ringformation from a primary alkoxy radical was observed. Experimental evidence supports the fact that the mode of ring opening of the oxiranyl carbinyl radical system is thermodynamically driven. B3LYP/6-31G* calculations indicate that the closed form of the radical is approximately
The Thermal Sulfenate−Sulfoxide Rearrangement: A Radical Pair Mechanism
作者:Jérôme Amaudrut、Olaf Wiest
DOI:10.1021/ja9940928
日期:2000.4.1
formation a radical pair by homolytic cleavage of the carbon−oxygen bond of the sulfenate. The two transient radicals formed then recombine to form the carbon−sulfur bond of the sulfoxide. The thermolysis of cinnamyl-4-nitrobenzenesulfenate has a positive entropy of activation (ΔS⧧ = 6.4 ± 2.0 eu in toluene), characteristic of a dissociative pathway. A normalsecondarykineticisotopeeffect (kH/kD =