Herein, we report the first facile Cu-free click reaction between alkynyl sulfonium and azide at ambient temperatures in aqueous media. DFT computations indicate that the sulfonium group is the key factor to gaining reactivity by stabilizing LUMO+1 and influencing the charge distribution of the triple bond. Sulfonium alkynes can be easily synthesized and scaled up, and most of them are biocompatible
Selective Catalysis of Thioether Oxidations with Dioxygen. Critical Role of Nitrosonium EDA Complexes in the Thermal and Photochemical Transfer of Oxygen Atom from Nitrogen Oxides to Sulfur Centers
作者:Eric Bosch、Jay K. Kochi
DOI:10.1021/jo00115a038
日期:1995.5
Various alkyl and aryl thioethers (R(2)S) are readily converted in high yields to sulfoxides in the presence of dioxygen and catalytic amounts of nitrogen dioxide. Separate experiments with stoichiometric amounts of reagents (under anaerobic conditions) establish the nitrosonium EDA complex [R(2)S, NO+] NO3- as the critical intermediate formed from the thioether-induced disproportionation of NO2. Low-temperature photoactivation by the deliberate irradiation of the charge-transfer absorption band of [R(2)S, NO+] NO3- leads to sulfoxide via the thioether cation radical. Electron transfer is also a viable route to the thermal (stoichiometric) oxidation of thioethers with NO2 via the same nitrosonium EDA complex. As such, Scheme 4 presents the complete sequence of redox changes of the nitrogen oxides in the catalytic conversion of thioether to sulfoxide via the cation radical.
Some Derivatives of Phenothiazine
作者:Henry Gilman、David A. Shirley
DOI:10.1021/ja01234a013
日期:1944.6
Ion radicals. XXXIII. Reactions of 10-methyl- and 10-phenylphenothiazine cation radicals with ammonia and amines. Preparation and reactions of 5-(N-alkyl)sulfilimines and 5-(N,N-dialkylamino)sulfonium salts
作者:Baldev K. Bandlish、A. Greg Padilla、Henry J. Shine
DOI:10.1021/jo00906a004
日期:1975.9
KNYAZEV V. N.; DROZD V. N.; MOZHAEVA T. YA., ZH. ORGAN. XIMII, 1979, 15, HO 12, 2561-2568