<i>p</i>-Toluenesulfonic Acid Adsorbed on Silica Gel: An Efficient Dehydrating Agent of Alcohols
作者:Franco D'Onofrio、Arrigo Scettri
DOI:10.1055/s-1985-31463
日期:——
Secondary and tertiary alcohols are efficiently dehydrated by reaction with p-toluenesulfonic acid supported on silica gel. In particular, the procedure allows the direct conversion of 3-hydroxy-steroids into Î2-olefins or Î3,5-dienes, without passing through the mesylate or tosylate esters.
In the presence of a catalytic amount of dioxo(tetramesitylporphyrinato)ruthenium(VI) complex, nitrousoxide (N2O) oxidized trisubstituted olefins into the corresponding epoxides in good-to-high yields with high selectivities.
Dinitrogen oxide was employed as a clean oxidant for various oxidations in the presence of a catalytic amount of dioxoruthenium tetramesitylporphyrin complex (Ru(tmo)(O) 2 ). A variety of olefins, secondary alcohols, and benzyl alcohols were smoothly oxidized to the corresponding epoxides, ketones, and aldehydes in high yields. In the oxidation of 9,10-dihydroanthracene derivatives, the competitive
Catalytic Access to Alkyl Bromides, Chlorides and Iodides via Visible Light-Promoted Decarboxylative Halogenation
作者:Lisa Candish、Eric A. Standley、Adrián Gómez-Suárez、Satobhisha Mukherjee、Frank Glorius
DOI:10.1002/chem.201602251
日期:2016.7.11
Herein is reported the catalytic, visiblelight‐promoted, decarboxylative halogenation (bromination, chlorination, and iodination) of aliphatic carboxylicacids. This operationally‐simple reaction tolerates a range of functional groups, proceeds at room temperature, and is redox neutral. By employing an iridium photocatalyst in concert with a halogen atom source, the use of stoichiometric metals such