Aminations of Aryl Halides Using Nitroaromatics as Coupling Partners: Overcoming the Hydrodehalogenation Pathway under a Hydrogen Atmosphere in Water

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(6), P. 4099 - 4107

Published: March 1, 2024

While overcoming hydrodehalogenation in a reductive environment, catalytic aqueous micellar technology has been developed for the C–N cross-coupling of nitroarenes with aryl halides. The bimetallic palladium–copper (Pd–Cu) nanocatalyst configuration micelles selectively facilitates highly selective amination pathway, possibly through situ formation Cu-hydride species as supported by nuclear magnetic resonance (NMR) spectroscopy. These prevent Pd-hydride-mediated even under molecular hydrogen atmosphere. thoroughly characterized using various spectroscopic and imaging tools, including 31P 1H NMR, X-ray absorption spectroscopy (XAS), high-resolution transmission electron microscopy. oxidation states Cu Pd needed desired selectivity have verified photoelectron spectroscopy, while metal–metal metal–ligand interactions XAS. Control experiments performed to determine significance each constituent on reaction pathway. As revealed control mass spectrometry, pathway does not involve azo- or nitroso-type intermediates. methodology can be applied numerous substrates broad functional protecting group tolerance.

Language: Английский

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Entropy reduction from strong localization – an explanation for enhanced reaction rates of organic synthesis in aqueous micelles

Journal of Colloid and Interface Science, Journal Year: 2022, Volume and Issue: 628, P. 819 - 828

Published: Aug. 18, 2022

The underlying mechanism for increased reaction rates in micellar catalysis-based organic synthesis is a reduced entropy barrier the reaction. A two-dimensional localization of reactants and catalyst surfactant micelle reduces translational all components. less intermediate than reactants, which leads to lower barrier.Quantum chemistry, COSMO-RS implicit solvent model statistical thermodynamics were employed predict stability range catalysts intermediates series micelles. localized linker region between lipophilic hydrophilic regions resulting decrease also calculated.The predicted proposed show that reduction larger prefactor rate can be significantly higher conventional an even when smaller volume temperatures typically needed under catalysis conditions are considered. results general across wide types reactions, selection surfactants commonly used synthesis, strongly supporting hypothesis.

Language: Английский

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API Syntheses in Aqueous Media: Assessing the Environmental Footprint en route from Academic Discovery to Industrial Applications as “Green Opportunity” for Process Chemistry

Organic Process Research & Development, Journal Year: 2023, Volume and Issue: 27(5), P. 822 - 830

Published: May 1, 2023

The use of designer surfactants to facilitate chemical transformations in water is a prime example for the knowledge transfer from academia industry. Accordingly, chemistry aqueous media aided by has emerged as viable alternative organic solvents part effort transform manufacturing into green art. While classical metrics indicate tremendous savings on waste generation, more exhaustive analysis including intrinsic carbon footprint such never been conducted. present work addresses this topic and outlines case study widely known applied working-horse surfactant chemistry, TPGS-750-M. Meanwhile, fate employed considered, holistic comparison drawn. key streamlined assessment reflected proper metrics, clearly pointing out nonzero chemistries media, though techniques range at greener end scale reaction media.

Language: Английский

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Switching Mechanistic Pathways by Micellar Catalysis: A Highly Selective Rhodium Catalyst for the Hydroaminomethylation of Olefins with Anilines in Water

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(4), P. 2702 - 2714

Published: Feb. 7, 2023

Hydroaminomethylation (HAM) is one of the most promising atom-economic processes for production secondary amines, which so far remains extremely challenging with anilines as substrates. Herein, we report use combined micellar and microwave catalysis HAM olefins in water reaction medium that allows synthesis good yields high regioselectivities. For rhodium/xantphos catalyst system, mechanistic investigations suggest a pathway different to commonly observed mechanisms homogeneous catalysts reported reaction, involving carbonylation initiated by C–H activation rather than classical hydroformylation steps.

Language: Английский

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Recent metallosurfactants for sustainable catalysis in water

Current Opinion in Colloid & Interface Science, Journal Year: 2023, Volume and Issue: 64, P. 101689 - 101689

Published: Feb. 25, 2023

In the field of green chemistry, micellar catalysis plays a central role for organic solvent replacement. Micelles ensure solubilization or dispersion catalyst and substrates in water imparting unique features terms chemo-, regio- stereoselectivity. For metal-catalyzed reactions, more robust approach recycling consists synthesis so called metallo-surfactants, which hydrophilic metal containing headgroup is endowed with hydrophobic ponytail, leading to formation metallo-micelles. This fast-growing research critically reviewed this contribution, describing new trends classifying literature since 2017 based on nature newly formed bond. Particular emphasis reported specific metallo-surfactants activities, selectivities recyclability self-assembling catalysts.

Language: Английский

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