To support the proposed hypothesis (Fig. ), emission quenching studies were performed, showing an interaction between the excited 3DPA2FBN* photocatalyst and the amine substrate (ethyl (4methoxyphenyl)glycinate; KSV = 30.4 M -1 ). According to the oxidation potentials of the excited photocatalyst (E1/2 (PC*/PC .-) = +0.92 V) and substrate (E1/2 = +0.63 𝑉 vs SCE) (see SI), the interaction is likely to be an oxidation (Fig. , I to II). To exclude that the interaction is dependent on a pre-complexation of substrate and photocatalyst (e.g. an EDA complex), UV-VIS and NMR spectra of both were measured separately and in mixture (Fig. and). No significant changes of the single components upon mixing were detected, rendering a pre-complexation unlikely. For the synthesis of amino alcohols, DABCO was employed as a base. Emission quenching reveals an interaction of the excited photocatalyst with DABCO as well (KSV = 14.3 M -1 ). However, comparing the Stern-Volmer constants, the amine is a significantly more potent quencher than DABCO (Fig. and). A single electron oxidation of the amine results in the formation of the corresponding radical cation (II).