Renewable ultrathin carbon nitride nanosheets and its practical utilization for photocatalytic decarboxylation free radical coupling reaction

[Display omitted] •Ultrathin carbon nitride nanosheets (CNS) with abundant active sites were synthesized.•Low-cost and green CNS was utilized as a substitution of organic photocatalysts.•Various 1,2-amino alcohols were obtained in good yields by using CNS as catalyst.•CNS catalyst could be recycled 7 times without significant loss of chemical yield.•The reusability and scale-up capacity confirmed industrial prospect of CNS. It is attractive to develop a durable and renewable carbon nitride-based photocatalytic system for compelling photocatalytic organic synthesis, but remains a huge challenge. In this study, cost-effective ultrathin carbon nitride nanosheets (denoted as CNS) with abundant active sites and visible light harvesting capacity were designed and prepared, with the aim of realizing the decarboxylation free radical coupling reaction between N-arylglycine and aldehydes. The as-prepared catalyst enabled good to high yields (up to 97%) of 1,2-amino alcohols with a wide substrate range and desired functional group tolerance. Furthermore, CNS provided a long-term durability, and could be straightforwardly recovered through simple centrifugation of reaction solutions. In addition, this practical strategy is also applicable to gram-scale photosynthesis as well as the synthesis of some other complex molecules, providing an alternative to homogeneous organic photocatalysts for the synthesis of valuable pharmaceutical intermediates for future applications.