74331-76-3Relevant academic research and scientific papers
Photoinduced rearrangement of vinyl tosylates to β-ketosulfones
Xie, Lili,Zhen, Xiaomeng,Huang, Shuping,Su, Xiaolong,Lin, Mai,Li, Yi
supporting information, p. 3530 - 3534 (2017/08/15)
We developed a photoinduced radical fragmentation and rearrangement of vinyl tosylates that enables efficient formation of β-ketosulfones. This process is based on the photoinitiated homolysis of vinyl tosylate to release a sulfinyl radical from the tosyl group and the subsequent addition of a sulfinyl radical to another vinyl tosylate to form the desired β-ketosulfones. This simple protocol features a broad scope with both aromatic and aliphatic substrates, convenient reagents and operating systems.
Vinyl Cation Intermediates in Solvolytic and Electrophilic Reactions. 1. Solvolysis of α-Arylvinyl Derivatives
Yates, Keith,Mandrapilias, George
, p. 3892 - 3902 (2007/10/02)
The solvolysis of 16 α-arylvinyl tosylates, bromides, and chlorides has been investigated in various alcohol-water mixtures and in acetic acid at several temperatures.All substrates were substituted with either 2-methyl or 2,6-dimethyl groups to accelerate the rates of reaction.The major or exclusive product isolated in most cases was the acetophenone arising from hydrolysis of the expected enol ethers or acetates during workup.The kinetics were simple first order in the vast majority of cases, with excess base added to prevent side reactions.Leaving group effects, Winstein-Grunwald m values, Schleyer Q values, and effects of solvent nucleophilicity all point to a limiting SN1 ionization generating a vinyl cation intermediate, in which there is little rear-side nucleophilic assistance by solvent.Substituent effects led to ρ values in the range -3.9 to -5.3 vs. ?+.Activation parameters are typical for an SN1 process, and ΔS% is insensitive to the presence of zero, one, or two o-methyl groups, as are the effects of solvent polarity on the rates.The results should therefore be directly comparable with other solvolytic or electrophilic reactions generating formally similar vinyl cation intermediates.
