Tetrazoles with oxygen-, sulfur-, and selenium-containing substituents

Visible-Light-Induced Organophotocatalytic Difunctionallization: Open-Air Hydroxysulfurization of Aryl Alkenes with Aryl Thiols

Herein, we report a regioselective visible-light-induced organophotoredox catalytic difunctionalization method to prepare β-hydroxysulfides using aryl alkenes and aryl thiols as substrates. The reaction provides a wide substrate scope of aryl alkenes (from simple styrene to complex bioactive compounds) and aryl thiols (from diverse heteroaromatic thiols to nonheteroaromatic thiols) (total 45 examples, up to 88% yield). Based on the combined experimental and computational studies, we demonstrate that in situ generated hydroperoxyl radicals from O₂ in air react with benzylic radicals, which restrains the reaction between benzylic radicals and the acidic form of thiols in a classical thiol-ene radical reaction. We show that difunctionalization is possible due to the choice of bases, diluted substrate concentrations, increment in catalyst loading, and selection of suitable aryl thiols under aerobic conditions. Considering the biological importance of heteroaromatic thiols and the lack of methods to install them, our approach offers a platform to derive various β-hydroxysulfides that contain aromatic elements.

Synthesis and Properties of Dichlorovinyl Derivatives of Tetrazoles

Abstract

1-Substituted 1H-tetrazole-5-thiols and 5-substituted 1H-tetrazoles easily reacted with trichloroethylene to form the corresponding S- and N-dichlorovinyl derivatives, respectively. In the case of 5-substituted 1H-tetrazoles, the reaction led to a mixture of 1- and 2-dichlorovinyltetrazoles. 5-Substituted-2-dichlorovinyltetrazoles are characterized by low thermal stability, but easily enter into the polymerization reaction.