Cobalt-Catalyzed Direct C-H Thiolation of Aromatic Amides with Disulfides: Application to the Synthesis of Quetiapine.

A direct C(sp2)-H thiolation of aromatic amides with disulfides was developed. The coupling reaction proceeds between the thioether radical and cobaltacycle intermediate. This method exhibits a relatively broad substrate scope and high functional group compatibility. A mechanistic study indicates that the cobalt(IV) intermediate is probably formed during the course of the reaction. The thiolation product can be transformed to Quetiapine, which is an atypical antipsychotic agent approved for the treatment of schizophrenia and bipolar disorder.