Dehydrogenation of Alkanes and Aliphatic Groups by Pincer-Ligated Metal Complexes

Chemical Reviews, Journal Year: 2017, Volume and Issue: 117(19), P. 12357 - 12384

Published: Sept. 27, 2017

The alkyl group is the most common component of organic molecules and difficult to selectively functionalize. development catalysts for dehydrogenation groups give corresponding olefins could open almost unlimited avenues functionalization. Homogeneous systems, or more generally systems based on molecular (including solid-supported) catalysts, probably offer greatest potential regio- chemoselective alkanes. progress date in this area has been achieved with pincer-ligated transition-metal-based catalysts; related chemistry are subject review. Chemists still far from achieving obvious perhaps attractive goal area, simple alkanes yield alkenes (specifically monoenes) high selectivity. Greater made tandem catalysis approaches which initial dehydrogenated product undergoes a desirable secondary reaction. Also reviewed substantial that closely substrates containing heteroatoms.

Language: Английский

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Tunable Triazole‐Phosphine‐Copper Catalysts for the Synthesis of 2‐Aryl‐1H‐benzo[d]imidazoles from Benzyl Alcohols and Diamines by Acceptorless Dehydrogenation and Borrowing Hydrogen Reactions

Advanced Synthesis & Catalysis, Journal Year: 2017, Volume and Issue: 359(19), P. 3332 - 3340

Published: May 26, 2017

Abstract Triazole‐phosphine‐copper complexes (TAP−Cu) have been synthesized and applied as tunable efficient catalysts for the selective synthesis of fluoro‐substituted 2‐aryl‐1 H ‐benzo[d]imidazole 1‐benzyl‐2‐aryl‐1 derivatives from simple alcohols in only one step. TAP−Cu exhibited excellent catalytic activity both dehydrogenation borrowing hydrogen reactions with more than 80 examples being demonstrated first time. It was observed that ligand played a critical role catalyst activity. Mechanistic studies deuterium labeling experiments indicated proceeded by an initial reversible alcohol resulting copper hydride intermediate. This also supported direct observation diagnostic signal solid‐state infrared spectroscopy. The TAP−Cu‐H complex showed absorptions at 912 cm −1 could be assigned to copper−hydride stretches. Furthermore, trapping intermediate bisimine successfully performed. magnified image

Language: Английский

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BINAP-copper supported by hydrotalcite as an efficient catalyst for the borrowing hydrogen reaction and dehydrogenation cyclization under water or solvent-free conditions

Green Chemistry, Journal Year: 2018, Volume and Issue: 20(11), P. 2571 - 2577

Published: Jan. 1, 2018

A BINAP-Cu system supported by hydrotalcite has been developed and proved to be a highly efficient catalyst for the atom-efficient green borrowing hydrogen reaction dehydrogenative cyclization.

Language: Английский

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Direct Reductive Quinolyl β-C–H Alkylation by Multispherical Cavity Carbon-Supported Cobalt Oxide Nanocatalysts

ACS Catalysis, Journal Year: 2017, Volume and Issue: 7(7), P. 4780 - 4785

Published: June 12, 2017

Until now, the selective (hetero)aryl C–H alkylation without assistance of directing groups or preinstallation functionalities still remains a highly challenging goal. Herein, by developing acid-resistant multispherical cavity carbon-supported cobalt oxide nanocatalysts (CoOx/MSCC) and hydrogen transfer-mediated activation mode for nonactivated N-heteroaromatics, we present direct reductive quinolyl isoquinolyl β-C–H with various aldehydes as alkylating agents. The catalytic transformation features broad substrate scope, good functional tolerance, use Earth-abundant reusable catalysts, no need prefunctionalizations, demonstrating that developed enable one to directly functionalize inert N-heteroaryl systems are difficult realize organometallic complexes.

Language: Английский

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Hydrogen‐Transfer‐Mediated α‐Functionalization of 1,8‐Naphthyridines by a Strategy Overcoming the Over‐Hydrogenation Barrier

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 56(45), P. 14232 - 14236

Published: Sept. 19, 2017

A general catalytic hydrogen transfer-mediated α-functionalization of 1,8-naphthyridines is reported for the first time that benefits from a activation mode non-activated pyridyl cores. The α-site selectively couples with C8-site various tetrahydroquinolines (THQs) to afford novel α-functionalized tetrahydro 1,8-naphthyridines, class synthetically useful building blocks and potential candidates discovery therapeutic bio-active products. utilization THQs as inactive donors (HDs) appears be key strategy overcome over-hydrogenation barrier address chemoselectivity issue. developed chemistry features operational simplicity, readily available catalyst good functional group tolerance, offers significant basis further development new protocols directly transform or functionalize inert N-heterocycles.

Language: Английский

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MOF-Derived Nanocobalt for Oxidative Functionalization of Cyclic Amines to Quinazolinones with 2-Aminoarylmethanols

ACS Catalysis, Journal Year: 2018, Volume and Issue: 8(7), P. 5869 - 5874

Published: May 25, 2018

By employing a MOF-templated method, we have developed highly dipersed and ultralow loading cobalt nanocatalyst, which has been applied in the oxidative functionalization of easily available cyclic amines with 2-aminoarylmethanols to ring-fused quinazolinones, core structures numerous valuable products. The catalytic transformation proceeds merits broad substrate scope, good functional group tolerance chemoselectivity, high step- atom-efficiency, use naturally abundant Co/O2 system, offers practical way for preparation quinazolinones structural diversity. work presented built an important basis direct conversion amine motifs into frameworks.

Language: Английский

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Unsymmetrical indazolyl-pyridinyl-triazole ligand-promoted highly active iridium complexes supported on hydrotalcite and its catalytic application in water

Green Chemistry, Journal Year: 2018, Volume and Issue: 20(8), P. 1805 - 1812

Published: Jan. 1, 2018

Herein, an indazolyl-pyridinyl-triazole ligand was synthesized and its iridium complex supported on hydrotalcite developed.

Language: Английский

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Merrifield resin-supported quinone as an efficient biomimetic catalyst for metal-free, base-free, chemoselective synthesis of 2,4,6-trisubstituted pyridines

Green Chemistry, Journal Year: 2019, Volume and Issue: 21(20), P. 5683 - 5690

Published: Jan. 1, 2019

Metal-free, base-free, biomimetic, and chemoselective synthesis of 2,4,6-trisubstituted pyridines was developed for the first time under mild conditions.

Language: Английский

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Preparation of pyridyltriazole ruthenium complexes as effective catalysts for the selective alkylation and one-pot C–H hydroxylation of 2-oxindole with alcohols and mechanism exploration

Organic Chemistry Frontiers, Journal Year: 2018, Volume and Issue: 5(18), P. 2668 - 2675

Published: Jan. 1, 2018

Pyridyltriazole-ligated ruthenium(ii) complexes have been designed and synthesized, which were characterized by X-ray crystallography.

Language: Английский

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Unsymmetrical triazolyl-naphthyridinyl-pyridine bridged highly active copper complexes supported on reduced graphene oxide and their application in water

Green Chemistry, Journal Year: 2019, Volume and Issue: 21(19), P. 5345 - 5351

Published: Jan. 1, 2019

A clean method for the synthesis of functionalized quinolines in water with a recoverable copper catalyst was developed.

Language: Английский

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