133301-36-7Relevant academic research and scientific papers
Cobalt-catalyzed chelation-assisted alkylation of arenes with primary and secondary alkyl halides
Gao, Ke,Yamakawa, Takeshi,Yoshikai, Naohiko
, p. 2024 - 2039 (2014/08/05)
Cobalt-N-heterocyclic carbene catalytic systems have been developed for chelation-assisted ortho-alkylation of aromatic compounds with alkyl halides. Aryl imines can be selectively monoalkylated at room temperature by various primary or secondary alkyl chlorides or bromides. The catalytic system can also be applied to 2-arylpyridine derivatives, which in the absence of steric hindrance are amenable to dialkylation by an excess of the alkyl halide. Mechanistic experiments, including reactions of stereochemical probes and radical clocks, indicate that the reaction involves single-electron transfer from the cobalt center to the alkyl halide to form the corresponding alkyl radical, which has a finite lifetime before it undergoes C-C bond formation. Georg Thieme Verlag Stuttgart, New York.
Cobalt-catalyzed ortho alkylation of aromatic imines with primary and secondary alkyl halides
Gao, Ke,Yoshikai, Naohiko
supporting information, p. 9279 - 9282 (2013/07/19)
We report here cobalt-N-heterocyclic carbene catalytic systems for the ortho alkylation of aromatic imines with alkyl chlorides and bromides, which allows the introduction of a variety of primary and secondary alkyl groups at room temperature. The stereochemical outcomes of the reaction of secondary alkyl halides suggest that the present reaction involves single-electron transfer from a cobalt species to the alkyl halide to generate the corresponding alkyl radical. A cycloalkylated product obtained by this method can be transformed into unique spirocycles through manipulation of the directing and cycloalkyl groups.
