Iodine‐Catalyzed Selective Synthesis of 2‐Sulfanylphenols via Oxidative Aromatization of Cyclohexanones and Disulfides

Abstract

Iodine-catalyzed intermolecular dehydrogenative aromatizations of six-membered cyclohexanA C H T U N G T R E N N U N G ones for the selective synthesis of 2-sulfanylphenols have been developed. Both aryl and alkyl disulfides can be used as sulfanylation reagents to give the desired products in good yields under the optimized reaction conditions. The catalytic reaction uses dimethyl sulfoxide or oxygen as the terminal oxidant and avoids the use of transition metal catalysts. In addition, a-sulfanyl enones could also be obtained via an iodine-catalyzed oxidative system from simple cyclic ketones using dimethyl sulfoxide as the oxidant.

Role of Lewis‐Base‐Coordinated Halogen(I) Intermediates in Organic Synthesis: The Journey from Unstable Intermediates to Versatile Reagents

“…Halogen‐based reagents have been used in the field of organic chemistry for a long time . So far, numerous applications of hypervalent halogens, mostly hypervalent iodine, have been explored.…”

Iodine, a Mild Reagent for the Aromatization of Terpenoids

“…The intermediacy of dienes 5a and 5b was strongly supported by the fact that these compounds, synthesized as depicted in Scheme , were found to give similar results to those observed for drimenol ( 1 ) when subjected to the optimized aromatization conditions (Table , entry 13). According to the mechanistic proposal and with the final aim of rendering this process catalytic in iodine, the recycling of HI to molecular iodine was attempted via the usage of oxidants other than DMSO, e.g., O 2 or TBHP (Table , entries 11, 12). However, no catalytic conditions were found, and the starting material was recovered as the main product after 12 h of reaction.…”

The Applications of Dimethyl Sulfoxide as Reagent in Organic Synthesis

“…Das and co‐workers revealed a PPh 3 ⋅HBr‐DMSO‐mediated efficient and chemoselective transformation of ketomethylene derivatives into flavones 73. Wei and co‐workers reported a selective synthesis of 2‐sulfanylphenols from non‐aromatic ketones 74. Braga and co‐workers reported an iodine‐catalyzed, metal‐free and solvent‐free method for the synthesis of a variety of unsymmetrical diorganyl chalcogenides under microwave irradiation 75.…”