Construction of Quinazoline‐Bridged Donor‐Acceptor Covalent Organic Frameworks for Photocatalytic Sulfoxide Synthesis from Alkenes and Thiols

As an emerging class of crystalline porous materials, COFs have attracted increasing attention in fields such as photocatalysis. Understanding how the linkage chemistry of COFs influences their construction and photoelectrochemical properties and photocatalytic performance remains a significant challenge. Herein, two quinazoline-linked COFs are assembled by the condensation of 1,3,6,8-tetra (4-formylphenyl) pyrene (TFPPy) with 3,3'-dibenzoyl-[1,1'-biphenyl]-4,4'-diamine (BD(Bz)) and 3,3'-dibenzoyl-4,4'-terphenyl diamine (BT(Bz)) respectively through a three-component reaction in the presence of an ammonia source. By integrating quinazoline linkage with pyrene structural unit, BD(Bz)-TFPPy-COF (COF-1b) and BT(Bz)-TFPPy-COF (COF-2b) exhibit electron donor-acceptor properties and possess high chemical stability as well, which demonstrated excellent photocatalytic performance for the selective synthesis of sulfoxides from alkenes and thiols. Incorporation of linkage chemistry and building blocks selection of COFs provides effective strategies for modulating its optoelectronic properties to improve photocatalytic performance.