Multiphotocatalyst Cascades: From Furans to Fused Butyrolactones and Substituted Cyclopentanones.

ABSTRACT

High value oxygenated polycycles have been rapidly and efficiently accessed from simple precursors in one pot processes. The reported methodology relies on a new and mild method for butenolide synthesis mediated by thiols. The initial photooxygenation and butenolide synthesis have been merged with subsequent photoredox reactions to achieve rare dual-photocatalyst cascades affording various fused butyrolactones. Ground state Lewis acid activity for methylene blue has been unveiled and then exploited in the synthesis of substituted cyclopentanones.