Micelle-mediated multicomponent cross-coupling in water: general construction of 3-chalcogenylindoles

A general and sustainable multicomponent cross-coupling for the construction of 3-chalcogenylindoles from indoles with aryl iodides and elemental sulfur under the aqueous micellar condition was developed. Elemental sulfur is employed as an eco-friendly and easy-handling sulfur source of thiyl radicals. The synergic effect between Cu catalysts and micelles formed by the sugar-based surfactant GluM can stabilize thiyl radicals, further initiating C-S coupling at the readily available indoles by single-electron transfer. Notably, the aqueous micellar system can not only be recycled and reused with good yields, but can also be extended to the conversion of elemental selenium.

Automated summary

A sustainable and general multicomponent cross-coupling method for the synthesis of 3-chalcogenylindoles from indoles using aryl iodides and elemental sulfur under aqueous micellar conditions is developed. Elemental sulfur serves as an eco-friendly and easy-handling sulfur source, generating thiyl radicals. The synergic effect between Cu catalysts and micelles formed by the sugar-based surfactant GluM stabilizes thiyl radicals, enabling C-S coupling with readily available indoles through single-electron transfer. The aqueous micellar system can be recycled and reused with good yields and can also be extended to the conversion of elemental selenium.