Coelectrolysis of CO2 with simple nitrogen compounds can generate molecules containing C–N bonds, which makes it an appealing method for increasing the value and scope of products obtained from CO2 electrochemical reduction (CO2ER) alone. In this study, we used density functional theory (DFT) calculations combined with a constant electrode potential model to investigate C–N formation pathways in the coreduction of CO2 and NO3 –/NO2 – to produce urea on Cu(111). Strikingly, we found that the first C–N bond is formed through coupling of gaseous CO2, rather than an intermediate of CO2ER, with the surface-bound N1 intermediates (i.e., *NO2, *NOH, *N, *NH, and *NH2) generated during NO3 –/NO2 – reduction to NH3. The reaction follows the Eley–Rideal mechanism and requires only a single active site. This result is in contrast with the literature, where the carbon species for C–N coupling were assumed to be intermediates from CO2ER to CO (i.e., *COOH and *CO). Further barrier decomposition analysis indicated that the facile kinetics of C–N coupling involving CO2 are due to the lower energy cost to deform CO2 and the N1 intermediate to the transition-state structure as well as the attractive interaction between them. For these facile and hence important CO2 + N1 reactions, we determined that the kinetic barrier of C–N coupling correlates well with the deformation energy of the N1 intermediate. Based on these insights, two strategies to improve C–N coupling have been proposed.

Gold-catalyzed reactions of cycloheptatrienes with nitrosoarenes yield nitrone derivatives efficiently. This reaction sequence enables us to develop gold-catalyzed aerobic oxidations of cycloheptatrienes to afford benzaldehyde derivatives using CuCl and nitrosoarenes as co-catalysts (10−30 mol %). Our density functional theory calculations support a novel nitroso-activated rearrangement, tropylium → benzylidene. With the same nitrosoarenes, we developed their gold-catalyzed [2 + 2 + 1]annulations between nitrosobenzene and two enol ethers to yield 5-alkoxyisoxazolidines using 1,4-cyclohexadienes as hydrogen donors.

A one-pot construction of bicyclo[3.2.1]oct-6-ene frameworks involves gold-catalyzed (4 + 3)-cycloadditions between 2-(1-alkynyl)-2-alken-1-ones and substituted cyclopentadienes; diastereoselectivity (dr >25:1) and enantioselectivity (up to 99.9% ee) are achieved with a chiral gold catalyst. Our DFT calculations suggest a three-step ionic mechanism for the cycloadditions of gold-containing 1,3-dipoles with cyclopentadienes, in which an exo-spatial arrangement is preferable.

Electrochemical partial oxidation of hydrocarbons to value-added products using electricity from renewable energy resources has the potential to change the way that commodity chemicals are manufactured. In this study, we used density functional theory calculations combined with a constant electrode potential model to study the previously reported ethylene partial electro-oxidation to epoxide on RuO2(110) in an aqueous solution containing [Cl–] = 0.3 M. We found that the high selectivity toward epoxide is due to the in situ generated *OCClO* intermediate that blocks parts of the surface and leads to isolation of *O (surface adsorbed oxygen) active sites. This step turns off the pathways to over-oxidation and drives the reaction toward epoxide formation. The reaction mechanisms for ethylene over-oxidation and partial oxidation are proposed. Our theoretical study unveiled a dynamic and unique means to achieve active site isolation that can be used to improve selectivity of hydrocarbon partial electro-oxidation.

A series of diindeno­[2,1-b:2′,1′-h]­biphenylenes with open-shell singlet ground states and interesting properties were prepared. The studied compounds consist of p-quinodimethane moieties, which suffer from geometric perturbation with bond angles of around 90°. The substituent effects on structural parameters, local aromaticity, and properties were systematically explored.