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Solar-light driven oxidation of benzylic alcohols over photocatalysts endows significant prospects in value-added organics evolution owing to its facile, inexpensive and sustainable ...process. However, the unsatisfactory performance of actual photocatalysts due to the inefficient charge separation, low photoredox potential and sluggish surface reaction impedes the practical application of this process. Herein, we developed an innovative Z-Scheme Cs3BiBr9 nanoparticles@porous C3N4 tubes (CBB-NP@P-tube-CN) heterojunction photocatalyst for highly selective benzyl alcohol oxidation. Such composite combining increased photo-oxidation potential, Z-Scheme charge migration route as well as the structural advantages of porous tubular C3N4 ensures the accelerated mass and ions diffusion kinetics, the fast photoinduced carriers dissociation and sufficient photoredox potentials. The CBB-NP@P-tube-CN photocatalyst demonstrates an exceptional performance for selective photo-oxidation of benzylic alcohol into benzaldehyde with 19, 14 and 3 times higher benzylic alcohols conversion rate than those of C3N4 nanotubes, Cs3Bi2Br9 and Cs3Bi2Br9@bulk C3N4 photocatalysts, respectively. This work offers a sustainable photocatalytic system based on lead-free halide perovskite toward large scale solar-light driven value-added chemicals production.
Two new oxovanadium and dioxomolybdenum Schiff base complexes, VOL(OMe) and MoO2L, were synthesized and characterized. Theoretical calculations were carried out by DFT at B3LYP/Def2-TZVP level of ...theory. Moreover, the catalytic activities of both complexes were investigated for the selective oxidation of benzylic alcohols using urea hydrogen peroxide (UHP) in acetonitrile.
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For the first time, two new oxovanadium and dioxomolybdenum Schiff base complexes, VOL(OMe) and MoO2L, were synthesized through the reaction of a ONO tridentate Schiff base ligand (H2L) derived from the condensation of 5-bromosalicylaldehyde and nicotinic hydrazide with oxo and dioxo acetylacetonate salts of vanadium and molybdenum, VO(acac)2 and MoO2(acac)2, respectively. The synthesized ligand and complexes were characterized by various spectroscopic techniques like FT-IR, 1H NMR, 13C NMR, elemental analysis (CHN) and the most authentic single crystal X-ray diffraction analysis (SC-XRD). The geometry around the central metal ion in MoO2L was distorted octahedral as revealed by the data collected from diffraction studies. Non-covalent interactions that are responsible for crystal packing are explored by Hirshfeld surface analysis. Theoretical calculations of the synthesized compounds, carried out by DFT at B3LYP/Def2-TZVP level of theory, indicated that the calculated results are in agreement with the experimental findings. Moreover, the catalytic activities of both complexes were investigated for the selective oxidation of benzylic alcohols using urea hydrogen peroxide (UHP) in acetonitrile.
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•A green photoredox oxidation of benzylic alcohols to carbonyl compounds with air as an oxidant was reported.•Broad substrates scope, 24 examples, up to 90% yields.•A quinuclidine ...mediated HAT process was involved in the mechanism.
A green photoredox oxidation of benzylic primary and secondary alcohols to aldehydes and ketones with air as an oxidant was reported. The oxidation shows broad substrate scope and excellent selectivity over benzylic alcohols to the aliphatic alcohols. Further mechanistic studies revealed a quinuclidine mediated HAT process, and blue LEDs promoted 4CzlPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene) photoredox cycle were involved in our oxidation.
Abstract
A gold-catalyzed formal (3+2) cycloaddition of benzylic alcohols with 1-phenylpropenes in an ionic liquid permits the environmentally friendly stereoselective synthesis of polysubstituted ...indanes in good yields and with high selectivity. The gold catalyst can be recycled at least five times.
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•Oxidation of aryl alkyl ketones and secondary benzylic alcohols into aryl carboxylic acids.•Iodine and Fe(NO3)3·9H2O as the catalysts, DMSO and oxygen as the oxidants.•Moderate to ...excellent yields can be obtained (up to 91%).
An interesting and convenient procedure for the oxidative transformation of aryl alkyl ketones and secondary benzylic alcohols to aryl carboxylic acids has been developed. By using iodine and Fe(NO3)3·9H2O as the catalysts, DMSO and oxygen as the oxidants, the desired aryl carboxylic acids were synthesized in moderate to excellent yields (up to 91%).
Selective oxidation of benzylic alcohols with proposed mechanism.
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•Synthesis of novel ONO tridentate Schiff base ligand and its oxovanadium and dioxomolybdenum ...complexes.•Characterization by FT-IR, 1H NMR, 13C NMR and CHN analysis.•Single crystal X-ray diffraction (SC-XRD) analysis of VOL and MoO2L complexes.•Hirshfeld surface analysis (HSA)•DFT calculation by B3LYP/Def2-TZVP method.•Comparison of experimental results with theoretical investigations.
Two new oxovanadium and dioxomolybdenum Schiff base complexes, VvO(L)(OCH3)(CH3OH) and MoVIO2(L)(CH2CH3OH), were synthesized by treating an ONO-donor type Schiff base ligand (H2L) derived by condensation of 5-nitrosalicylaldehyde and nicotinic hydrazide with oxo and dioxo acetylacetonate salts of vanadium and molybdenum, VO(acac)2 and MoO2(acac)2, respectively. The synthesized ligand and complexes were characterized by various spectroscopic techniques like FT-IR, multinuclear (1H, 13C) NMR, elemental analysis and the most authentic single crystal X-ray diffraction analysis. In both complexes the geometry around the central metal ions was distorted octahedral as revealed by the data collected from diffraction studies. Theoretical calculation of the synthesized compounds were carried out by DFT as well as TD-DFT using B3LYP method by employing the Def2-TZVP basis set. The findings of theoretical data indicated that the calculated results are in accordance with the experimental findings. Moreover, the catalytic efficiencies of both complexes were investigated by oxidizing the benzylic alcohols in the presence of urea hydrogen peroxide (UHP) in acetonitrile.
Matteson Homologation of Arylboronic Esters Kinsinger, Thorsten; Kazmaier, Uli
European journal of organic chemistry,
August 19, 2022, Letnik:
2022, Številka:
31
Journal Article
Recenzirano
Odprti dostop
Commercially available arylboronic acids can easily be converted into chiral boronic esters which can be subjected to Matteson homologations using Grignard reagents. The best results are obtained in ...one pot protocols without isolation of the α‐chloroboronic ester intermediates. Alkoxides can also be used as nucleophiles, but the corresponding homologated boronic esters are found to be not stable.
Under optimized conditions, chiral esters of commercially available arylboronic acids can be subjected to Matteson homologations in a one‐pot protocol using Grignard reagents without significant side reactions.
An efficient protocol was developed for Pd-catalyzed direct C–H bond acylation by cross-dehydrogenative-coupling of arylbenzothiazoles and benzylic alcohols using tert-butyl hydroperoxide (TBHP) as ...the oxidant. The acylation reactions exhibit good reactivities and excellent regioselectivity.
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This study aims to report the first gallium‐catalyzed direct reduction of benzylic alcohols using isopropanol as a reductant. The reaction proceeds via gallium catalyst‐assisted hydride transfer of ...the in situ‐generated benzylic isopropyl ether. The method generates only water and acetone as byproducts and thus provides an atom‐economic and environmentally friendly approach to the synthesis of di‐ and triarylmethanes, which are important substructures in various bioactive compounds and functional materials.
