Copper‐Catalyzed Electrophilic Cyclization of N‐Propargylamines with Sodium Sulfinate for the Synthesis of 3‐Sulfonated Quinolines

Abstract

A convenient and effective protocol for the synthesis of 3‐sulfonated quinolines via copper‐catalyzed electrophilic cyclization of N‐propargylamines has been developed, in which cheap and stable sodium sulfinates were utilized as green sulfonylation reagents. This cascade transformation involves radical addition, cyclization and dehydrogenative aromatization processes in a one‐pot reaction under mild conditions.

Recent Progress in Sulfonylation via Radical Reaction with Sodium Sulfinates, Sulfinic Acids, Sulfonyl Chlorides or Sulfonyl Hydrazides

“…In 2019, the copper-catalyzed cyclization of N-propargylamines for the synthesis of 3-sulfonated quinolines was developed by Zhang group. [33] Both aryl and alkyl sodiumsulfinates reacted well in this system. This cascade transformation which involves radical addition, cyclization and dehydrogenative aromatization processes can be realized in a one-pot reaction under mild conditions (Scheme 25).…”

“…In 2019, the copper‐catalyzed cyclization of N‐propargylamines for the synthesis of 3‐sulfonated quinolines was developed by Zhang group [33] . Both aryl and alkyl sodiumsulfinates reacted well in this system.…”

Synthesis and applications of sodium sulfinates (RSO2Na): a powerful building block for the synthesis of organosulfur compounds

“…A variety of N -propargylamines smoothly underwent the ring-closing sulfonylation with various aryl or alkyl sodium sulfinates and afforded a series of 3-sulfonylquinoline derivatives in moderate to high yields ( Scheme 215A ). 323 More recently, Huang and co-workers also developed an alternative metal-free method for 3-sulfonated quinolines via visible-light irradiation of N -propargylanilines with sodium sulfinates. Eosin-Y catalyzed the wide-spread construction of 3-sulfonylquinolines in good to high yields by the ring-closing sulfonylation of various N -propargylanilines with sodium aryl and alkyl sulfinates ( Scheme 215B ).…”

Oxidative Sulfonylation of Multiple Carbon‐Carbon bonds with Sulfonyl Hydrazides, Sulfinic Acids and their Salts

“…[277] A wide range of 3-sulfonyl quinolines 530 were obtained as a result of sulfonylation-cyclization-aromatization of N-propargyl anilines 528 with aromatic sulfonyl hydrazides 529 under the action of TBHP in DCE at 90°C under air (Scheme 228). [278] A similar process was also carried out under visible light irradiation [279] and the CuI/TBHP [280] system using sulfinic acids or their sodium salts as sources of sulfonyl radicals. Benzo[f] [1,7]naphthyridines were synthesized from N-propargyl 3-aminoquinolines using the KI/TBHP system.…”