A novel iron-mediated direct C–H arylation of quinones and pyridine analogues with arylboronic acids has been developed using dichloromethane and water as solvents at ambient temperature. FeS is employed and serves as an efficient catalyst. A detailed reaction mechanism is speculated and expounded.
Direct Arylation of Substituted Pyridines with Arylboronic Acids Catalyzed by Iron(II) Oxalate
作者:Yibo Huang、Dan Guan、Liang Wang
DOI:10.1002/cjoc.201400528
日期:2014.12
The directarylation of substitutedpyridines with several arylboronicacids has been developed. This transformation could proceed readily at ambient temperature using inexpensive reagents: iron(II) oxalate as a catalyst, potassium persulfate as a co‐oxidant, which can afford the arylated products in mild to good yields. The mechanism is presumed to proceed through a nucleophilic radical addition to
Synthesis of Sterically Hindered Primary Amines by Concurrent Tandem Photoredox Catalysis
作者:Michael C. Nicastri、Dan Lehnherr、Yu-hong Lam、Daniel A. DiRocco、Tomislav Rovis
DOI:10.1021/jacs.9b10871
日期:2020.1.15
methodologies exist for amine synthesis, but the direct synthesis of primary amines with a fully substituted α carbon center is an underdeveloped area. We report a method which utilizes photoredox catalysis to couple readily available O-benzoyl oximes with cyanoarenes to synthesize primary amines with fully substituted α-carbons. We also demonstrate that this method enables the synthesis of amines with α-trifluoromethyl
Electrochemical Synthesis of Hindered Primary and Secondary Amines via Proton-Coupled Electron Transfer
作者:Dan Lehnherr、Yu-hong Lam、Michael C. Nicastri、Jinchu Liu、Justin A. Newman、Erik L. Regalado、Daniel A. DiRocco、Tomislav Rovis
DOI:10.1021/jacs.9b10870
日期:2020.1.8
Accessing hindered amines, particularly primary amines α to a fully substituted carbon center, is synthetically challenging. We report an electrochemical method to access such hindered amines starting from benchtop-stable iminium salts and cyanoheteroarenes. A wide variety of substituted heterocycles (pyridine, pyrimidine, pyrazine, purine, azaindole) can be utilized in the cross-coupling reaction
In the past years, the activations of aromaticnitriles for radical arylations under photoirradiation have been developed. We here report the first example of radical arylations using aromaticnitriles without the assistance of photoirradiation. Importantly, with this method, the direct arylation of C(sp3)–H in benzyl amines provided a practical method for the synthesis of diarylmethylamines without