Generation and intramolecular cyclization of α-phenylsulfenyl and α-alkylsulfenyl radicals
作者:Yeun-Min Tsai、Fu-Chang Chang、Jimin Huang、Chi-Lung Shiu、Chai-Lin Kao、Jyh-Shiunn Liu
DOI:10.1016/s0040-4020(97)00156-7
日期:1997.3
alpha-Phenylsulfenyl radicals are generated by the reaction of diphenyl dithioacetals or phenyl alpha-chlorosulfides with tributyltin hydride. Alkyl phenyl dithioacetals react selectively with tributyltin hydride to give alpha-alkylsulfenyl radicals. 5-Exo-type of intramolecular cyclizations of these radicals are studied. The cyclization is most successful when the olefin is terminally substituted with an ester group. The cis/trans ratio of the cyclized product varies according to the reaction rates. With a faster cyclization, cis-isomer is the major product. A slower cyclization gives more trans-product. (C) 1997 Elsevier Science Ltd.
Carmack, Marvin; Behforouz, Mohammad; Berchtold, Glenn A., Journal of Heterocyclic Chemistry, 1989, vol. 26, p. 1305 - 1318
作者:Carmack, Marvin、Behforouz, Mohammad、Berchtold, Glenn A.、Berkowitz, Samuel M.、Wiesler, Donald、Barone, Ralph
DOI:——
日期:——
Asymmetric induction in thia-Diels-Alder reactions of chiral polyfluoroalkylthionocarboxylates
作者:Vadim M. Timoshenko、Sergiy A. Siry、Alexander B. Rozhenko、Yuriy G. Shermolovich
DOI:10.1016/j.jfluchem.2009.11.011
日期:2010.2
A series of chiral S- or O-alkyl thionoesters have been synthesized by treatment of trifluorothioacetyl- or 2,2,3,3-tetrafluorothiopropionyl chloride with corresponding thiols or alcohols. The thia-Diels-Alder reaction of the thionoesters with symmetrical 1,3-dienes proceeds with diastereoselectivity up to 60%. Structures of cycloaddition products and corresponding transition states have been studied at the DFT level of approximation. The experimentally observed diastereomeric excess has been referred to differences in activation energies of transition states, preceding formation of the diastereomeric cycloaducts. (C) 2009 Elsevier B.V. All rights reserved.
Sen, Science and Culture, <hi>1935</hi>, vol. 1, p. 435
作者:Sen
DOI:——
日期:——
Sen, Journal of the Indian Chemical Society, 1935, vol. 12, p. 647,650