Abstract The local electric field generated at organic-inorganic hybrid interfaces can profoundly influence electrocatalytic reactions, yet how molecular interfaces regulate local field distributions and reaction pathways remains poorly understood. Here, we combine grand-canonical density functional theory with in situ surface-enhanced Raman spectroscopy to investigate CO2 reduction at cobalt phthalocyanine-copper (CoPc-Cu) interfaces. Density functional theory calculations show that CoPc creates a confined interfacial microenvironment and modifies the charge distribution at the Cu surface, producing non-uniform local electric fields that are experimentally probed using the vibrational Stark effect of adsorbed CO. Theory and experiment reveal that this field heterogeneity modifies CO adsorption across neighboring Cu sites and increases the adsorption-energy difference between adjacent CO intermediates, thereby lowering the barrier for C–C coupling. Consistent with this mechanism, CoPc-Cu exhibits an enhanced C2+/C1 product ratio, particularly at modest cathodic potentials where the confined hybrid interface is preserved. This work provides direct in situ evidence that organic-inorganic hybrid interfaces can regulate electrocatalytic selectivity through local electric-field engineering, offering design principles for field-enhanced CO2 electroreduction.
Abstract A gold-catalyzed dearomative cyclization of indoles with ynone-nitriles assisted by a Lewis or a Brønsted acid has been developed, which provides an efficient route to 4-azafluorenones via an unexpected indole ring-opening process. The key strategy involves the attack of an iminyl intermediate to the indoleninium species at its highly electrophilic C2 position, with both intermediates being generated spontaneously during the dearomatization process. By varying the gold catalyst and acid additives, the 1+1 and 2+1 component reactions can be achieved selectively.
Abstract The design of metal–support interfaces is critical for overcoming the persistent trade-off between CO2 conversion and methanol selectivity in CO2 hydrogenation. Though an inverse catalyst with an oxide-on-metal configuration provides a platform for tuning interfacial properties, the distinct roles of multi-interfaces with different electronic properties and how they collectively govern reaction pathways remain largely unexplored. Herein, we constructed an inverse Ga2O3-ZnO/Cu catalyst to engineer dual pathways for efficient CO2-to-methanol conversion. Comprehensive characterization reveals that Ga2O3 induces charge redistribution in the catalyst for more oxygen vacancies, which enhance CO2 adsorption. The Cu-ZnO interface facilitates the formation of key intermediates along the formate pathway. Meanwhile, Ga also introduces a RWGS + CO* hydrogenation pathway to preferentially convert CO2 to methanol. In addition, Ga2O3 loading-enabled smaller Cu nanoparticles further enhanced H2 dissociation and spillover on the surface. Consequently, the optimized Ga2O3-ZnO/Cu catalyst achieves a high space time yield of methanol (728.73 gCH3OH kgcat–1 h–1) with a high methanol selectivity of 82.37% at 220 °C and 3 MPa. This work provides insights into engineering reaction pathways for methanol synthesis via the rational design of synergistic active sites.
Abstract Herein, we report a metal-free, cooperative oxidized graphitic carbon nitride/l-proline catalysis for enantioselective dearomative oxyalkylation of 2-arylindoles. The developed method leverages the band structure of g-C3N4 to efficiently generate singlet oxygen (1O2) under visible light and aerobic conditions, driving an oxidative dearomatization cascade. The resulting intermediates are intercepted via an l-proline-mediated Mannich addition, providing direct access to C2-quaternary indolin-3-ones in high yields (up to 88%) and with enantioselectivities (up to 99% ee). By integrating heterogeneous carbon nitride photocatalysis with asymmetric organocatalysis, this protocol offers a robust, recyclable alternative to traditional noble-metal catalysis for enantioselective synthesis of C2-quaternary indolin-3-ones.
Transition-metal-catalyzed cyclization of 1,n-enynes represents a versatile platform for the construction of structurally diverse chiral heterocycles. Despite substantial advances in this field, the enantioselective cyclizative alkylation of 1,n-enynes remains a formidable synthetic challenge, primarily due to the inherent difficulty in simultaneous control of regio-, chemo-, and stereoselectivity. Herein, we disclose a highly enantioselective cyclizative alkylation of 1,6-enynes employing two complementary alkylating reagents: diazo compounds and readily available alkyl iodides. This protocol proceeds under mild conditions and features broad substrate scope, delivering enantioenriched γ-lactams and pyrrolidine derivatives bearing quaternary stereogenic centers in good yields (up to 81%) and enantioselectivities (53 examples, up to 98% ee). Mechanistic studies corroborate that these two types of alkylating reagents follow entirely distinct catalytic pathways.
