The Cp*IrIII-catalyzed coupling of terminal alkenes with dioxazolones to achieve C–H amidation was studied theoretically with the aid of the density functional calculations. Employing the Ir=nitrenoid intermediate species involved in the reaction mechanism, the Ir– –N–R bonding nature was analyzed based on LUMO/HOMO interactions. Especially, the branch-selectivity with Cp*Ir(III) as the catalyst, the influence of Ir(III) vs Rh(III) on branch/linear selectivity, and the impossibility of aziridination were elucidated. This work provided further understanding and beneficial information for designing novel related selective reactions.

Density functional theory calculations have been performed to explore the Ru-catalyzed decarbonylative annulation reaction of 3-hydroxy-2-phenyl-chromone with an alkyne to synthesize spiroindenebenzofuranones. A Ru(II) Ru(0) Ru(II) rather than a Ru(II) Ru(IV) Ru(II) transformation was found involved in the decarbonylation process, which is responsible for the sequence of alkyne insertion/decarbonylation. Oxidative addition of C (carbonyl) C(carbonyl) bond to Ru(0) and the Ru(II) C(sp2) bond formation were confirmed to be favorable for the decarbonylation, meanwhile oxidative addition of C (carbonyl) C(carbonyl) bond to Ru(0) is likely to be the ratedetermining step for the entire catalytic cycle. It is predicted that the regeneration of the catalyst was achieved by the oxidation of air oxygen in the absence of other oxidants. The current theoretical study provides new insights into the decarbonylative annulation.

An atom economical approach for the synthesis of α-carbolin-4-ones has been developed. This process was realized via a C–N bond cleavage/intramolecular amination cascade. During this process, one C–N and one C–C bond are cleaved and two C–N and two C–C bonds are formed. Mechanistic studies suggested a migrative N-cyclization process involving a carbene intermediate.

A theoretical and computational study was performed on the nitrene-participating three-component carboamination of dienes. The reaction proceeds mainly through C–H activation, olefin insertion, metal nitrenoid formation, and selective C–N coupling. The role of solvent effect enables the extrusion of carbon dioxide to generate the key metal nitrenoid being not concerted but stepwise. The Rh = N was indicated by HOMO-LUMO interactions that the backdonation is dominant and hence showing the electron withdrawing behavior of nitrene. Regioselectivity for C–C bond formation, E-type product, and 1,4-carboamination was discussed.

Cu-catalyzed aerobic epoxidation offers cost-effective access to epoxides, a class of versatile chemical building blocks. Herein, a computational mechanistic study was performed to investigate Cu-catalyzed aerobic epoxidation of tertiary allylic alcohols and ethers. In contrast to the previously proposed solvent−O2 cascade activation and the O2-activation mechanisms, a substrate− O2−solvent cascade activation mechanism was revealed for not only high-strained substrates but also low- and nonstrained substrates tested herein. Specifically, it involves an induction period for the in situ generation of the actual catalyst, a Cu(II)- alkylperoxide complex derived from solvent 1,4-dioxane. Three substrate-activation pathways, depending on the substrate strain and the presence or absence of an allylic hydroxyl group, were found to be operative in this period. For the actual catalytic epoxidation, the mononuclear Cu(II) pathway was found to be favored over the dinuclear Cu(III)-oxo pathway and

1,4-Dicarbonyl motifs are notoriously difficult to synthesize, yet the mechanistic underpinnings of conventional electron donor– acceptor (EDA) strategies remain contentious. Here, we unambiguously resolve this debate and disprove the hydrogenbonding EDA (H-EDA) mechanism for decarboxylative acylation of activated alkenes with α-keto acids, establishing a concerted proton-coupled electron transfer (PCET) pathway as the exclusive operative mechanism. A combination of spectroscopic, electrochemical, photophysical, and computational studies provides definitive evidence against EDA/H-EDA formation and electron transfer, while DFT calculations revealed an exceptionally low activation barrier for concerted PCET (ΔG‡/ΔE‡ = 5.1–11.6 kcal mol-1), consistent with high efficiency under mild conditions. This photocatalyst- and base-free visible-light protocol enables rapid assembly of diverse 1,4-dicarbonyl compounds, with broad substrate scope, exceptional functional group compatibility, and reli

Here, an unpresented non-C1 synthon function of CO2 is reported to facilitate electrochemical defluorination. The introduction of CO2 modulates the electron distribution of the radical anion intermediate generated through one-electron reduction, thereby weakening the reduction potential and facilitating reduction and defluorination. CO2 is released subsequently via spontaneous decarboxylation to complete its promotion role. The presented results shed light on a distinctive utilization of CO2, which may stimulate interest in developing non-C1 synthon functions of CO2.

A KOtBu-mediated C2-benzylation of quinoline N-oxides with benzylboronates under mild reaction conditions has been developed. The reaction shows broad scope for both of the quinoline N-oxides and benzylboronates, especially, secondary and tertiary benzylboronates are also compatible with this reaction. DFT calculations indicate that the reaction is promoted by the nucleophilic addition of KOtBu to boronate rather than the deprotonation of benzylic C−H bond with KOtBu.

Cu-catalyzed aerobic epoxidation offers cost-effective access to epoxides, a class of versatile chemical building blocks. Herein, a computational mechanistic study was performed to investigate Cu-catalyzed aerobic epoxidation of tertiary allylic alcohols and ethers. In contrast to the previously proposed solvent−O2 cascade activation and the O2-activation mechanisms, a substrate− O2−solvent cascade activation mechanism was revealed for not only high-strained substrates but also low- and nonstrained substrates tested herein. Specifically, it involves an induction period for the in situ generation of the actual catalyst, a Cu(II)- alkylperoxide complex derived from solvent 1,4-dioxane. Three substrate-activation pathways, depending on the substrate strain and the presence or absence of an allylic hydroxyl group, were found to be operative in this period. For the actual catalytic epoxidation, the mononuclear Cu(II) pathway was found to be favored over the dinuclear Cu(III)-oxo pathway and

1,4-Dicarbonyl motifs are notoriously difficult to synthesize, yet the mechanistic underpinnings of conventional electron donor– acceptor (EDA) strategies remain contentious. Here, we unambiguously resolve this debate and disprove the hydrogenbonding EDA (H-EDA) mechanism for decarboxylative acylation of activated alkenes with α-keto acids, establishing a concerted proton-coupled electron transfer (PCET) pathway as the exclusive operative mechanism. A combination of spectroscopic, electrochemical, photophysical, and computational studies provides definitive evidence against EDA/H-EDA formation and electron transfer, while DFT calculations revealed an exceptionally low activation barrier for concerted PCET (ΔG‡/ΔE‡ = 5.1–11.6 kcal mol-1), consistent with high efficiency under mild conditions. This photocatalyst- and base-free visible-light protocol enables rapid assembly of diverse 1,4-dicarbonyl compounds, with broad substrate scope, exceptional functional group compatibility, and reli

Here, an unpresented non-C1 synthon function of CO2 is reported to facilitate electrochemical defluorination. The introduction of CO2 modulates the electron distribution of the radical anion intermediate generated through one-electron reduction, thereby weakening the reduction potential and facilitating reduction and defluorination. CO2 is released subsequently via spontaneous decarboxylation to complete its promotion role. The presented results shed light on a distinctive utilization of CO2, which may stimulate interest in developing non-C1 synthon functions of CO2.

A KOtBu-mediated C2-benzylation of quinoline N-oxides with benzylboronates under mild reaction conditions has been developed. The reaction shows broad scope for both of the quinoline N-oxides and benzylboronates, especially, secondary and tertiary benzylboronates are also compatible with this reaction. DFT calculations indicate that the reaction is promoted by the nucleophilic addition of KOtBu to boronate rather than the deprotonation of benzylic C−H bond with KOtBu.