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A new oxygen bridged [Cu‐O‐Ba] bimetallic catalyst is synthesized. The novel catalyst is used for Csp2‐O cross‐coupling reactions of phenols with haloarenes. Iodo‐, bromo‐, and unactivated chloro‐arenes could be coupled with aryl phenols efficiently in high yield. Moreover, functional groups were well tolerated using this protocol. The catalyst is Eco‐friendly, air stable, recyclable and efficient. [ABSTRACT FROM AUTHOR]

In this work, an oxo‐bridged bimetallic CuMoO4 catalyst for Csp2−Se cross‐coupling of diaryldiselenides with aryl‐halides is reported. The current discovery is noteworthy, as the catalyst is eco‐friendly, easily accessible, air‐stable, and recyclable. The methodology exhibits broad substrate scope and the catalytic system tolerates common functional groups. The protocol uses aryl iodide and bromides as electrophile instead of boronic acids. This is the first example of using an oxo‐ bridged copper based bimetallic catalyst for Csp2−Se cross‐coupling reactions in water. C−Cl bond remains intact during reaction. [ABSTRACT FROM AUTHOR]

Most non-palladium catalysts employed in Sonogashira cross-coupling work at high temperatures of 120–140 °C and with well-defined ligands. Palladium-based catalysts with bulky and electron-rich phosphine ligands generally show the best performance for the above-mentioned cross-coupling procedure. Herein, we report a new protocol for Csp–Csp2 Sonogashira cross-coupling between a terminal alkyne and aryl halide using the cheap and commercially available catalyst CuSeO3·2H2O. The title reaction proceeds using a variety of terminal alkynes, affording diaryl or aryl–alkyl acetylenes in high yields under mild conditions in the absence of ligands. Alkyl acetylenes, ethynylsilanes, and alkynols are efficiently coupled with aryl iodides and aryl bromides. The mechanism of the reaction was evaluated using computational DFT studies. To the best of our knowledge, this is the first example of the use of an oxygen-bridged copper-based bimetallic catalyst for Csp–Csp2 Sonogashira cross-coupling reactions under mild conditions. The reaction is palladium-free up to a limit of 0.2 ppm. [ABSTRACT FROM AUTHOR]

Though concept of oxygen bridged bimetallic catalyst for organic reaction is not well understood. Herein, we have tried to explain the concept by experimental as well as its support by full DFT study. We report here a competent protocol for dehydrogenative oxidation of benzylic alcohol using an oxygen bridged bimetallic CuMoO4 nano catalyst. Careful demonstration reveals that oxidation is not effective either with mono‐metallic Cu (II) or Mo(VI); instead combination of both the metals through the oxygen bridge [Cu−O−Mo] unexpectedly and interestingly catalyzed the reaction efficiently. The new concept is strongly supported by computational DFT study. DFT study reveals dehydrogenative oxidation is preferred at copper centre over molybdenum and aromatic benzyl alcohols are greatly stabilised. Interaction barrier energy of monometallic CuO and MoO3 catalyst is much higher than bimetallic CuMoO4. Hydrogen transfer has larger barrier heights for CuO (31.5 kcal/mol) and MoO3 (40.3 kcal/mol) than bimetallic CuMoO4. [ABSTRACT FROM AUTHOR]

Herein, we report a new protocol for the dehydrogenative oxidation of aryl methanols using the cheap and commercially available catalyst CuSeO3·2H2O. Oxygen-bridged [Cu–O–Se] bimetallic catalysts are not only less expensive than other catalysts used for the dehydrogenative oxidation of aryl alcohols, but they are also effective under mild conditions and at low concentrations. The title reaction proceeds with a variety of aromatic and heteroaromatic methanol examples, obtaining the corresponding carbonyls in high yields. This is the first example using an oxygen-bridged copper-based bimetallic catalyst [Cu–O–Se] for dehydrogenative benzylic oxidation. Computational DFT studies reveal simultaneous H-transfer and Cu–O bond breaking, with a transition-state barrier height of 29.3 kcal mol−1. [ABSTRACT FROM AUTHOR]

CuII catalyst is less efficient at room temperature for C−S cross‐coupling. C−S cross‐coupling by CuII catalyst at room temperature is not reported; however, doping of copper with molybdenum metal has been realized here to be more efficient for C−S cross‐coupling in comparison to general CuII catalyst. The doped catalyst CuMoO4 nanoparticle is found to be more efficient than copper. The catalyst works under mild conditions without any ligand at room temperature and is recyclable and effective for a wide range of thiols and haloarenes (ArI, ArBr, ArF) from milligram to gram scale. The copper‐based bimetallic catalyst is developed and recognized for C−S cross‐coupling of haloarenes with alkyl and aryl thiols. [ABSTRACT FROM AUTHOR]