Abstract

An exceptional efficiency of pyrazine-annelated porphyrin as a general photocatalyst for the oxidation of organic sulfides is demonstrated. It is shown that phosphonate-substituted pyrazinoporphyrin 2H-1 brings together sufficient photostability and high efficiency in the aerobic photooxidation of a series of various sulfides. The influence of the reaction conditions onto the efficiency of homogeneous sulfide photooxidation in the presence of the photosensitizer (PS) was investigated and strong dependence on the solvent system was observed. The use of methanol is required for the photocatalytic sulfoxidation and the ratio of the alcohol/other solvent can significantly affect the conversion and selectivity of the reaction. The application of the prepared PS in 0.001 mol % loading allowed achieving complete conversion (97-100 %, turnover number up to 1,00,000, turnover frequency up to 6250 h-1) of substrates bearing substituents of different nature, namely aromatic and aliphatic sulfides with donor or acceptor substituents and substituents prone to oxidation, as well as cyclic sulfides. The selectivity of the of the corresponding sulfoxides formation of 96-100 % was revealed. Finally, a gram-scale synthesis of several sulfoxides was successfully performed with the PS under investigation, providing desired products in 66-96 % yield with over 98 % purity.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.