Metal-Free, Initiator-Free Graphene Oxide-Catalyzed Trifluoromethylation of Arenes
作者:Jingyu Zhang、Yun Yang、Jingxian Fang、Guo-Jun Deng、Hang Gong
DOI:10.1002/asia.201700939
日期:2017.10.5
The direct C−H trifluoromethylation of arenes catalyzed by graphene oxide (GO) under safe conditions is described. This strategy is metal‐free, initiator‐free, safe, and scalable. It employs a readily available CF3 source and the reaction can be easily controlled to obtain a mono‐trifluorinated product. This method opens a new avenue for GO‐catalyzed chemistry.
Cross-Dehydrogenative-Coupling of Alkoxybenzenes with Toluenes: Copper(II) Halide Mediated Tandem Halo/Benzylation of Arenes
作者:Thomas E. Storr、Christopher J. Teskey、Michael F. Greaney
DOI:10.1002/chem.201603783
日期:2016.12.12
with concomitant halogenation is reported. Conditions employed were the use of stoichiometric copperhalide salts and dialkylperoxides to afford a range of bromoalkoxydi‐ and triarylmethanes. Preliminary mechanistic studies suggest that the in situ production of haloarenes (or dihaloarenes) followed by a copper‐mediated coupling of a benzylic radical is operational.
Dirhodium(II)-catalyzed ortho C–H amination of N,N-dialkylanilines has been developed. Stericallycongested 1,2-diaminobenzenes were obtained in high yields with excellent chemo- and regioselectivities from para-substituted anilines and even from para-unsubstituted anilines. The ortho selectivity observed was rationalized in terms of the interaction between the dialkylamino group and a Rh(II)–nitrene
A process for the preparation of phloroglucinol is disclosed. The process comprises reacting hexachlorobenzene with sodium propylate or sodium isopropylate, in a molar ratio of from about 1:3 to about 1:20, in an aprotic solvent, at a temperature from about 50 to about 250.degree. C., to form trichlorophloroglucinol tripropylether, or trichlorophloroglucinol triisopropylether. The latter compounds are dechlorinated to form phloroglucinol tripropylether or phloroglucinol triisopropylether, with the use of metallic sodium, and subsequently hydrolyzed to form phloroglucinol.