漂流

Two transformations initiated by photoinduced one-electron transfer to α-bromo ketones have been demonstrated. Hantzsch esters donate one electron to α-bromo ketones under photoirradiation, promoting reductive debromination. Subsequent reactions of the resulting radical species of the ketones with molecular oxygen and Hantzsch esters lead to α-hydroxylation or debromination, respectively. The relative dominance of the two pathways depends profoundly on the reaction conditions, including solvent, O₂ levels, and the concentration of the Hantzsch esters. The synthetic protocols feature advantages because they require the environmentally benign sources, molecular oxygen and visible light.

Direct CH amidation of arylphosphoryl compounds has been developed by using an Ir^III catalyst system under mild conditions. A wide range of substrates could be employed with high functional-group tolerance. This procedure was successfully applied for the first time to the asymmetric reaction giving rise to a P-chirogenic center with a high diastereomeric ratio of up to 19:1 (90 % de).

A road to­ P-chirality: A cationic [Ir^III(Cp*)] complex catalyzes the direct CH amidation of diarylphosphorus compounds bearing a chiral auxiliary to allow for a straightforward route to optically pure P-chiral compounds (see scheme; Cp*=1,2,3,4,5-pentamethylcyclopentadiene).

An efficient and transition-metal-free approach was developed to access a series of fluorinated heteroaromatics in moderate to excellent yields. This one-pot procedure features a triple-relay transformation of rapid dearomatization, fluorination, and rearomatization processes, which represents a conceptually novel strategy of combining partial hydrogenation and electrophilic fluorination.

An efficient and transition-metal-free approach was developed to access a series of fluorinated heteroaromatics in moderate to excellent yields through formal substitution of a nitro group by fluorine (see scheme). This one-pot procedure features a triple-relay transformation of rapid dearomatization, fluorination, and rearomatization processes, which represents a conceptually novel strategy of combining partial hydrogenation and electrophilic fluorination.

Various methylarenes were transformed into the corresponding aromatic nitriles in good to moderate yields by the treatment with aq. HBr and aq. H₂O₂, followed by reaction with molecular iodine and aq. ammonia in a one-pot procedure. The present reaction is a useful, practical, transition-metal-free, and organic-reagent-free method for the preparation of aromatic nitriles from methylarenes.

Various methylarenes were treated with aq. HBr and aq. H₂O₂ under warming conditions and/or irradiation conditions, followed by the reaction with molecular iodine and aq. ammonia, to provide the corresponding aromatic nitriles, in a one-pot procedure. The present reaction was carried out under metal-free and organic-reagent-free conditions.