Our experimental investigation commenced with the optimization of the photoredox-catalyzed styrene carboamidation reaction. After extensive screening of all relevant reaction parameters (for further information, see Supporting Information, section 5.1), it was found that the difunctionalized product 4 could be obtained in 50% yield when an acetonitrile solution (0.1 M) of the 3-phenylpropanoic acid NHPI derivative 1a (1.0 equiv.) as a primary radical precursor, 4-trifluoromethyl styrene 2a (1.2 equiv.) as a radical acceptor, 1,2,3,5-tetrakis (carbazol-9-yl)-4,6-dicyanobenzene (4-CzIPN, 5 mol%) as a photocatalyst and trifluoroacetic acid (TFA, 10 equiv.) was irradiated with blue LEDs (40W, 427 nm Kessil lamp) for 16 h (Table , entry 1). Remarkably, the more expensive organophotocatalyst 4-DPAIPN or transition metal-based photocatalyst Ir(ppy)3 gave inferior yields (entries 2-3). Altering the equivalents of TFA did not affect the reaction efficiency, whereas its omission resulted in complete suppression of the process (entry 4), consistent with the previously proposed role of the Brønsted acid in activating 1a towards SET reduction and its involvement in the Ritter-type step (cf. Figure ). Various other Brønsted acid additives were screened, all giving either lower yields or complex crude mixtures (see Supporting Information, Table ). To explore the possibility to extend our methodology to acid-sensitive substrates, different additives were tested (see Supporting Information, Table ), revealing zinc trifluoroacetate hydrate Zn(CF3COO)2 . xH2O(50 mol%) as a costeffective and suitable Lewis acid for the transformation (entry 5). Reversing the stoichiometry of 1a and 2a did not affect the yield but increased the formation of hydroalkylation by-product S1a (31% in Table ). This strongly implicated that a hydrogen atom transfer (HAT) process was responsible for forming S1a, where the incipient benzyl radical after Giesetype addition (II in Figure ) receives a hydrogen atom from one of the activated CH2 groups in 1a. Finally, no desired product was observed in absence of the photocatalyst (entry 7). Having established the optimal reaction conditions, we next investigated the scope of the three-component carboamidation of 2a with a variety of RAEs derived from readily available carboxylic acids (Figure ). Initial efforts focused on modifications of the phenyl-bearing alkyl chain in 1a. Given the significance of alkyl chain length in influencing critical properties for agro-and biochemical applications, phenyl propanoic, butanoic, pentanoic and hexanoic acid derivatives were successfully incorporated into the C=C double bonds, resulting in synthetically useful yields (products 4, 6-8), with the structure of 4 confirmed by single crystal XRD analysis.