2-(4-Chloro­phen­yl)-1,5-diphenyl-3-tosyl­imidazolidin-4-one

In the title compound, C28H23ClN2O3S, the central imidazolidine ring adopts a twisted conformation and the S atom has distorted tetra­hedral geometry. The crystal packing is stabilized by C—H⋯O, C—H⋯π and π–π inter­actions [centroid–centroid distance = 3.8302 (10) Å]

Pyridinic-nitrogen on ordered mesoporous carbon: A versatile NAD(P)H mimic for borrowing-hydrogen reactions

Metal-free carbonaceous materials are an emerging class of heterogeneous catalysts for sustainable chemistry. However, designing such catalytic materials with unique properties for specific organic transformations remains a challenge due to an inadequate understanding of their active sites. Herein, we report our studies on the use of nitrogen-doped ordered mesoporous carbons as a biomimetic novel heterogeneous catalyst for the borrowing-hydrogen or hydrogen-auto-transfer class of cascade reactions. These redox neutral processes have gained prominence owing to their high atom economy and sustainability. Our experimental investigations, supported by computer modelling, show that the local nitrogen environment, i.e., the benzannulated pyridine substructures on the edges/defects of the carbon matrices, play a critical role as catalytic hydrogen shuttles in borrowing-hydrogen reactions mimicking the role of the NAD(P)+/NAD(P)H redox couple

Copper-Catalyzed Ring-Expansion Cascade of Azirines with Alkynes: Synthesis of Multisubstituted Pyridines at Room Temperature

The first intermolecular ring-expansion cascade of azirines with alkynes for the synthesis of pyridines, enabled by a copper/triethylamine catalytic system via simultaneous generation and utilization of yne-enamine and skipped-yne-imine intermediates, is reported. Experimental as well as computational mechanistic studies revealed that the role of triethylamine is crucial in deciding the reaction pathway toward the pyridine products. This process offers a novel, one-step, direct, and practical strategy for the rapid construction of highly substituted pyridines under exceedingly mild conditions, and an installed alkyne functionality