Photocatalysis in a multi-capillary assembly microreactor: toward up-scaling the synthesis of 2H-indazoles as drug scaffolds

Visible-light-promoted direct arylation of 2H-indazoles using phenyldiazonium salt enabled a single-step and fast synthesis (<1 min) of C3 arylated products in high yields (>65%) in an eosin Y immobilized capillary microreactor.