title: Cobalt-catalyzed ortho alkylation of aromatic imines with primary and secondary alkyl halides.
abstract: 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.
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Ke
authors.initials: K
authors.lastname: Gao
authors.forename: Naohiko
authors.initials: N
authors.lastname: Yoshikai
mesh_terms: D000447:Aldehydes / Q000138:chemical synthesis* / Q000737:chemistry; D000478:Alkylation; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D006841:Hydrocarbons, Aromatic / Q000138:chemical synthesis* / Q000737:chemistry; D006842:Hydrocarbons, Brominated / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D006841:Hydrocarbons, Aromatic; D006842:Hydrocarbons, Brominated; D006843:Hydrocarbons, Chlorinated; D007097:Imines; D009942:Organometallic Compounds; D003035:Cobalt