Benzothiazole-Linked Metal-Free Covalent Organic Framework\nNanostructures for Visible-Light-Driven Photocatalytic Conversion\nof Phenylboronic Acids to Phenols

Abstract

Herein, we have reported two benzothiazole-linked\ncovalent organic\nframework nanostructures (BTZ-BCA-COF and BTZ-TPA-COF), which have\nbeen prepared <i>via</i> a highly efficient one-pot, multicomponent\ntransition-metal-free C–H functionalization and oxidative annulation\nsynthetic strategy and employing elemental sulfur as one of the key\ncomponents. These prepared COFs are highly crystalline in nature,\nhave high surface area, and are chemically stable. These COFs exhibit\nlight-harvesting capacity as a photosensitizer for visible-light-assisted\n“carbon–boron” bond cleavage with a high functional\ngroup tolerance of the substrates. In order to acquire in-depth understanding\nabout the mechanistic pathway involved and for comparison in photocatalytic\nperformance, we have performed <i>in situ</i> electron paramagnetic\nresonance and studies. Our contribution sheds light on exploration\nof elemental sulfur to extended π-conjugation network-based\nphotocatalysts, followed by instigating their structural uniqueness–photocatalytic\nactivity relationship.