Cobalt-catalyzed directed alkylation of arenes with primary and secondary alkyl halides

• Main Authors: Yoshikai, Naohiko, Gao, Ke
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2014
• Subjects: DRNTU::Science::Chemistry::Organic chemistry
• Online Access: https://hdl.handle.net/10356/105074; http://hdl.handle.net/10220/20375
• Institution: Nanyang Technological University

A cobalt–N-heterocyclic carbene catalyst allows ortho-alkylation of aromatic imines with unactivated primary and secondary alkyl chlorides and bromides under room-temperature conditions. The scope of the reaction encompasses or complements that of cobalt-catalyzed ortho-alkylation reactions with olefins as alkylating agents that we developed previously. Stereochemical outcomes of secondary alkylation reactions suggest that the 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 group and the cycloalkyl groups.