Zhao Y, Zhang J, Zhang J, Zhang Z, Liu R. Iodine-Catalyzed Cyclization of
o-Nitrothiophenols with Cyclohexanones to Phenothiazines.
J Org Chem 2024. [PMID:
38773694 DOI:
10.1021/acs.joc.4c00039]
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Abstract
Here, a novel iodine-catalyzed direct cyclization of o-nitrothiophenols with cyclohexanones to phenothiazines has been described without external oxidants and hydrogen acceptors. The nitro of o-nitrothiophenol works as both a hydrogen acceptor and a coupling group, and water is the only byproduct. The reaction involves the reduction of nitro groups, C-H bond thioetherification, and C-H bond dehydroaromatization. This scheme offers broad synthetic value for further elaborations, as exemplified by a 3-step total synthesis of antipsychotic chlorpromazine.
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