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The generation of an iminium from amines is a way to functionalize the α carbon by coupling reactions. The reaction mechanism of the conversion of tertiary amines to iminium with CuCl2(H2O)2as catalyst in aerobic conditions has been computationally and experimentally studied in this work. This process is initiated by the oxidation of the amine to a radical cation dichlorocuprate through the reduction of CuIIto CuI. Then, the iminium dichlorocuprate is generated from the radical-ion through a hydrogen-transfer. The H atom can be accepted by molecular oxygen or by a second molecule of catalyst (in anaerobic conditions). Therefore, O2also assumes the important role of acceptor along with that of regenerator of the catalyst. The experimental study confirmed the computational study and lead to the synthesis of four new molecules from the cross-coupling of N,N-diethyl- and N,N-diisoproylaniline with nitromethane and dimethylmalonate.

A new database, VROA36, is introduced to investigate the performance of computational approaches for vibrational Raman optical activity (VROA) calculations. The database is composed of 36 molecules with known experimental VROA spectra. It includes 93 conformers. Normal modes calculated with B3LYP-D3(BJ)/def2-TZVP are used to compute the VROA spectra with four functionals, B3LYP-D3(BJ), ωB97X-D, M11, and optimally tuned LC-PBE, as well as several basis sets. SimROA indices and frequency scaling factors are used to compare calculated spectra with each other and with experimental data. The four functionals perform equally well independently of the basis set and usually achieve good agreement with the experimental data. For molecules in near- or at-resonance conditions, the inclusion of a complex (damped) linear response approach is important to obtain physically meaningful VROA intensities. The use of any of the tested functional approximations with the def2-SVPD Gaussian-type basis set, or a basis of similar flexibility, can be recommended for efficient and reliable theoretical VROA studies.