Cysteine Quantum Dots Nano-photocatalyst mediated Newman Kwart Rearrangement under Ambient Conditions

Classical Newman Kwart rearrangement requires harsh reaction conditions (high temperature), resulting in substrate decomposition/side product formation, limiting the scope to electronically deficient substrates to stabilize the anionic transition state in the thermal processes. It becomes imperative to develop amicable protocols for this reaction. The immense potential of nanomaterials as dynamic heterogeneous catalysts, coupled with the scope of photo-mediated transformations, provides a unique opportunity to tackle this challenge. In continuation of our efforts to develop the field of nanomaterials mediated photocatalysis, we fabricated carbon dots as nanocatalysts to mediate the reaction at ambient temperature in a very short time frame. Our method was more compatible with electron-rich substrates, corroborating the operation of a cationic mechanism (although electronically neutral substrates were also facile participants in the reaction). The material could retain its activity up to ten runs. This study exemplifies the potential of nanomaterials in mediating otherwise critical synthetic strategies as well.