Treatment of deactivated aromatic compounds with Nbromosuccinimide in trifluoroacetic acid solvent in the presence of sulfuric acid gave the corresponding monobromoaromatic compounds in good to excellent yields.

Fluoroform, CHF3, a non-ozone-depleting, nontoxic, and inexpensive gas can be used as a difluorocarbene source in a process for the conversion of phenols and thiophenols to their difluoromethoxy and difluorothiomethoxy derivatives. The reactions are carried out at moderate temperatures and atmospheric pressure, using potassium hydroxide as base in a two-phase (water/dioxane or water/acetonitrile) process to provide moderate to good yields of the respective products.

Spiro[cyclopropane-l,2 '-adamantane-1 '-ol] (6a). The synthesis of this compound follows essentially the procedure for the preparation of 13. Purification of the crude reaction product by chromatography on alumina and recrystallization from petroleum ether yields 70-80% of 6a: mp 192-194°( lit.8 mp 192-194°); ir (CCU) 3550, 3400, 3050, 1110, 1085, 1010, 975, 935 cm"1 2; nmr (CCU) 0.1 and 0.85 (2 g, 2.3 and 2, C3íU ring), 1.15 (broad s, 1), 1.75 (m, 6), 2.1 (m, 7); mass spectrum mje 178.

No abstract

The first example of photoredox catalyzed difluoromethylation of unactivated alkenes coupled with C-C bond formation to an aryl ring is reported. The reactions are conducted under mild conditions and afford tetralin derivatives bearing difluoromethyl as well as other fluoroalkyl groups in good to high yields. In addition, the study indicates that 6-exo radical cyclization of an alkyl radical to a phenyl ring is faster than the respective 5-exo radical cyclization. A computational study provides insights to the experimental results.