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In the present work, bimetallic CuNi‐12 (1 : 2 molar ratio of Cu : Ni) was synthesized via a liquid‐phase reduction method and utilized for the efficient and selective hydrogenation of biomass‐derived aldehydes and ketones with 2‐propanol as hydrogen source and KOH as base. The synergistic effect between copper and nickel metal enhanced the catalytic activity and selectivity. Bimetallic CuNi‐12 nanocatalyst is highly efficient and sustainable for converting various aldehyde and ketones with 100 % conversion and selectivity. Biomass derived alcohol i. e. furfural, cinnamaldehyde, 5‐hydroxy methyl furfural were utilized as substrate and converted into alcohol with 100 % conversion and selectivity. Bimetallic nanocatalyst CuNi‐12 having high surface area and it is reusable, magnetically separable and recyclable up to seven cycles. [ABSTRACT FROM AUTHOR]

• Recent developments for organic transformations employing SACs are summarized. • Cost-effective, earth-abundant 3d transition metal SACs are discussed. • Hydrogenation, oxidation, hydrogen production and coupling reactions are discussed. • Catalytic mechanistic pathways using SACs are highlighted in the review. Single-atom catalysts (SACs) show potential applications for various organic transformation reactions due to their easy recyclability, high exposure to active sites, and unique electronic structures. Owing to highly exposed active sites, SACs exhibit superior catalytic activity and chemoselectivity compared to metal nanoparticles. This mini-review comprehensively outlines the recent progress in chemoselective hydrogenation, dehydrogenation, C C and C N cross-coupling reactions, peroxymonosulfate activation, production of hydrogen and ammonia by employing 3d transition metals such as Co, Cu, Fe, Ni-based SACs. These reactions are key steps in organic synthetic chemistry and pharmaceutical industries, and utilizing earth-abundant 3d-metal SACs without compromising the selectivity and activity made these reactions cost-effective, sustainable, and industrially applicable. We also illustrate the mechanistic pathways for these reactions and highlight the key challenges and future opportunities to improve the existing SACs. Moreover, we believe that this review may help to address the existing issues of chemoselectivity in organic synthesis as well as promote the development of SACs. [Display omitted] [ABSTRACT FROM AUTHOR]

The development of bimetallic and magnetic nanomaterials as a catalyst is highly desirable for organic transformations due to their recyclability for the sustainable future of chemical industries. Bimetallic CoNi nanoflowers were developed via the facile liquid‐phase reduction method and were employed for the hydrogenation of terminal alkynes. The structural and morphological studies were analyzed by X‐ray diffraction, Field‐Emission Scanning Electron Microscopy, and High Resolution Transmission Electron Microscopy. The bimetallic CoNi nanoflower exhibited 100 % conversion with ∼100 % selectivity towards alkane products with recyclability up to six cycles. The transfer hydrogenation mechanism was proposed via diimide formation with Co(0)/Ni(0) state, confirmed by X‐ray Photoemission Spectroscopy analysis. [ABSTRACT FROM AUTHOR]

MCM‐41‐supported ZnO−Cu(OH)Cl nanoparticles were synthesized via an incipient wetness impregnation technique using zinc chloride and copper chloride salts as well as water at room temperature. The catalyst was characterized by powder X‐ray diffraction (PXRD), infrared spectroscopy (IR), and TGA, whereas surface and morphological studies were performed by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The above studies revealed the incorporation of metal species into the pores of MCM‐41, leading to a decrease in surface area of the nanoparticles that was found to be 239.079 m2/g. The substituents attached to the ketone determine the rate of the reaction, and the utilization of the green solvent 'water' astonishingly completes the hydrogenation reaction in 45 minutes at 40 °C with 100% conversion and 100% selectivity as analyzed by gas chromatography‐mass spectrometry. Hence, ZnO−Cu(OH)Cl/MCM‐41 nanoparticles with 2.46 wt% zinc and 6.39 wt% copper were demonstrated as an active catalyst for the reduction of ketones without using any gaseous hydrogen source making it highly efficient as well as environmentally and economically benign. [ABSTRACT FROM AUTHOR]

• Photoredox catalyst corroborate with another organic and inorganic catalyst for hydrogen production. • Noble metal-based catalysts for hydrogenation and borrowing hydrogen strategies. • MOFs of earth-abundant transition metal catalysts for the transfer hydrogenation. • Semiconductor nanocatalysts and organocatalysts cooperation with photoredox catalysts. The corroboration between the transition metal catalysts and photocatalysts also termed as metalla-photocatalysis has dispensed new directions to the contemporaneous synthetic chemists in revolutionizing our chemical manufacturing set-ups. In new cooperative alliance facilitated by advanced materials providing novel synthetic protocol for facile access to photoexcited reactive radical intermediates under moderate reaction conditions. These transition metal molecular photoredox catalysts cooperatively interact with another metal catalysts, organocatalysts or semiconductor photocatalysts to effectively promote selective organic synthesis. Recently, hydrogen borrowing reactions like transfer hydrogenation and acceptorless dehydrogenation reactions have been critically evaluated for more sustainable and benign chemical manufacturing. Furthermore, acceptorless dehydrogenation or borrowing hydrogen reactions have received considerable attention for the fabrication of organic molecules for eco-friendly and benign protocol for the energy storage and transport. Therefore, binary and ternary photoredox catalytic systems have been developed for clean chemical manufacturing and energy storage and transport. The present review article focuses on the recent developments in the applications of the photoredox catalysts for transfer hydrogenation and acceptorless dehydrogenation reactions. [Display omitted] [ABSTRACT FROM AUTHOR]