Redox-Adaptive Auto-Tandem Catalysis: Ce(III)/Ce(IV) Interconversion-Mediated Integration of Nazarov Cyclization and Oxidative Hydroxylation

Tandem
catalysis combines multiple chemical transformations into
a single reaction sequence, offering significant advantages. However,
tandem catalysis using a single catalyst remains challenging. We introduce
a redox-adaptive strategy for autotandem catalysis employing a single
homogeneous cerium catalyst to achieve the one-pot synthesis of α-hydroxylated
cyclopentenones under mild aerobic conditions. The step-economical
process integrates Ce(III)-mediated Nazarov cyclization with Ce(IV)-mediated
oxidative hydroxylation through autonomous redox interconversion.
The redox-adaptive behavior of cerium facilitates efficient transitions
between distinct ionic and radical mechanisms. The obtained multifunctional
products enable further skeletal modifications, demonstrating the
utility of the proposed method for synthesizing complex molecular
structures.