Photophysical and Electrochemical Properties of Pyrimidopteridine‐Based Organic Photoredox Catalysts.

Herein we describe the synthesis and photophysical and electrochemical characterization of pyrimidopteridine‐based photoredox catalysts. The pyrimidopteridines can be obtained from the corresponding N‐oxides through photo‐mediated oxygen atom transfer to a sacrificial acceptor molecule on gramscale. The presence of a triplet excited state was evidenced by means of transient absorption spectroscopy. Pyrimidopteridines are potent excited state oxidants with excited state reduction potentials exceeding +2.10 V vs. SCE in MeCN. The catalytic activity is illustrated in the photo‐mediated oxidative annulation of 2‐phenylbenzoic acid. [ABSTRACT FROM AUTHOR]