Zr-Oxo Cluster-Based Metal-Organic Framework for Selective C(sp3)-H Bond Photooxidation.

Abstract

Selective aerobic oxidation of C(sp3)-H bonds to carbonyl compounds is an important but challenging transformation in green and sustainable catalysis, owing to the difficulty of achieving high chemoselectivity while suppressing overoxidation under mild conditions. Herein, we report HEBMU-1, a Zr-oxo cluster-based metal-organic framework photocatalyst, for the selective photooxidation of alkanes, arenes, and heteroarenes to aldehydes and ketones. Benefiting from its robust crystalline framework, photoactive organic linkers, and accessible Zr-oxo cluster sites, HEBMU-1 enables light harvesting, enhanced photoinduced charge separation, and molecular oxygen activation under xenon lamp irradiation at room temperature. This catalytic system exhibits broad substrate scope, good functional-group tolerance, high chemoselectivity, and effective suppression of overoxidation, affording the corresponding carbonyl products in good to high yields. The use of molecular oxygen as a green oxidant avoids stoichiometric chemical oxidants and harsh reaction conditions. In addition, HEBMU-1 can be readily recovered and reused over multiple cycles while maintaining its structural integrity. This work demonstrates the potential of Zr-oxo cluster-based MOF photocatalysts for selective aerobic C(sp3)-H oxidation and provides a green strategy for the synthesis of value-added carbonyl compounds.