Direct Synthesis of Amides by Acceptorless Dehydrogenative Coupling of Benzyl Alcohols and Ammonia Catalyzed by a Manganese Pincer Complex: Unexpected Crucial Role of Base

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(31), С. 12202 - 12206

Опубликована: Июль 15, 2019

Amide synthesis is one of the most important transformations in chemistry and biology. The direct use ammonia for incorporation nitrogen functionalities organic molecules an attractive environmentally benign method. We present here a new amides by acceptorless dehydrogenative coupling benzyl alcohols ammonia. reaction catalyzed pincer complex earth-abundant manganese presence stoichiometric base, making overall process economical, efficient, sustainable. Interesting mechanistic insights based on detailed experimental observations, indicating crucial role are provided.

Язык: Английский

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Direct dehydrogenative alkyl Heck-couplings of vinylarenes with umpolung aldehydes catalyzed by nickel

Nature Communications, Год журнала: 2019, Номер 10(1)

Опубликована: Фев. 12, 2019

Abstract Alkenes are fundamental functionalities in nature and highly useful intermediates organic synthesis, medicinal chemistry material sciences. Transition-metal-catalyzed Heck couplings with halides as electrophiles have been established a powerful protocol for the synthesis of this valuable building block. However, requirement generation stoichiometric hazardous halide wastes may cause significant sustainable concerns. The halide-free oxidative alkenylations involving organometallics or arenes coupling partners provide facile alternative pathway. Nonetheless, amounts extra oxidant essential most cases. Herein, we present direct dehydrogenative alkyl Heck-coupling reaction under oxidant-free conditions, liberating hydrogen, nitrogen water side products. Excellent regioselectivity is achieved via neighboring oxygen atom coordination. Broad substrate scope, great functional group (ketone, ester, phenol, free amine, amide etc) tolerance modification pharmaceutical candidates biological molecules exemplified its generality practicability.

Язык: Английский

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Immobilization of manganese dioxide nanoparticles on modified poly 2,4-dichlorostyrene microspheres: a highly efficient and recyclable catalyst for borrowing hydrogen reactions

Organic Chemistry Frontiers, Год журнала: 2019, Номер 6(19), С. 3420 - 3427

Опубликована: Янв. 1, 2019

Modified poly 2,4-dichlorostyrene microspheres were designed and synthesized, proved to be an effective carrier synthesize supported manganese dioxide nanoparticles.

Язык: Английский

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A Phosphine-Free Air-Stable Mn(II)-Catalyst for Sustainable Synthesis of Quinazolin-4(3H)-ones, Quinolines, and Quinoxalines in Water

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(8), С. 5250 - 5265

Опубликована: Март 30, 2024

The synthesis, characterization, and catalytic application of a new phosphine-free, well-defined, water-soluble, air-stable Mn(II)-catalyst [Mn(L)(H2O)2Cl](Cl) ([1]Cl) featuring 1,10-phenanthroline based tridentate pincer ligand, 2-(1H-pyrazol-1-yl)-1,10-phenanthroline (L), in dehydrogenative functionalization alcohols to various N-heterocycles such as quinazolin-4(3H)-ones, quinolines, quinoxalines are reported here. A wide array multisubstituted quinazolin-4(3H)-ones were prepared water under air following two pathways via the coupling with 2-aminobenzamides 2-aminobenzonitriles, respectively. 2-Aminobenzyl alcohol ketones bearing active methylene group used partners for synthesizing quinoline derivatives, quinoxaline derivatives by vicinal diols 1,2-diamines. In all cases, reaction proceeded smoothly using our [1]Cl air, affording desired satisfactory yields starting from cheap readily accessible precursors. Gram-scale synthesis compounds indicates industrial relevance synthetic strategy. Control experiments performed understand unveil plausible mechanism.

Язык: Английский

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Olefins from alcohols via catalytic acceptorless dehydrogenation coupling reactions

Catalysis Science & Technology, Год журнала: 2024, Номер 14(8), С. 2064 - 2089

Опубликована: Янв. 1, 2024

Recent advances in efficient catalytic routes to olefins from alcohols (A2O) are highlighted.

Язык: Английский

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Manganese‐Catalyzed Selective Upgrading of Ethanol with Methanol into Isobutanol

ChemSusChem, Год журнала: 2019, Номер 12(13), С. 3069 - 3072

Опубликована: Фев. 6, 2019

Abstract Isobutanol serves as an ideal gasoline additive owing to its good compatibility with current engine technology, high energy density, and octane number. Herein, efficient selective Mn‐catalyzed upgrading of ethanol methanol into isobutanol is reported. This the first example deoxygenative coupling lower alcohols by using a homogeneous non‐noble‐metal catalyst. transformation proceeded at very low catalyst loading turnover number (9233) up 96 % selectivity.

Язык: Английский

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Transfer Hydrogenation of Carbonyl Groups, Imines andN‐Heterocycles Catalyzed by Simple, Bipyridine‐Based Mn^IComplexes

ChemCatChem, Год журнала: 2019, Номер 11(16), С. 3844 - 3852

Опубликована: Март 18, 2019

Abstract Utilization of hydroxy‐substituted bipyridine ligands in transition metal catalysis mimicking [Fe]‐hydrogenase has been shown to be a promising approach developing new catalysts for hydrogenation. For example, Mn I complexes with 6,6′‐dihydroxy‐2,2′‐bipyridine ligand have previously active CO 2 In this work, simple bipyridine‐based were developed that act as transfer hydrogenation ketones, aldehydes and imines. the first time, Mn‐catalyzed N ‐heterocycles was reported. The highest catalytic activity among variously substituted observed complex bearing two OH groups bipyridine. Deuterium labeling experiments suggest monohydride pathway.

Язык: Английский

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Manganese(III) Porphyrin‐Catalyzed Dehydrogenation of Alcohols to form Imines, Tertiary Amines and Quinolines

Chemistry - A European Journal, Год журнала: 2019, Номер 25(25), С. 6439 - 6446

Опубликована: Март 19, 2019

Manganese(III) porphyrin chloride complexes have been developed for the first time as catalysts acceptorless dehydrogenative coupling of alcohols and amines. The reaction has applied to direct synthesis imines, tertiary amines quinolines where only hydrogen gas and/or water are formed by-product(s). mechanism is believed involve formation a manganese(III) alkoxide complex which degrades into aldehyde hydride species. latter reacts with alcohol form thereby regenerates complex.

Язык: Английский

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Nickel-Catalyzed Regioselective Hydrobenzylation of 1,3-Dienes with Hydrazones

ACS Catalysis, Год журнала: 2019, Номер 9(10), С. 9199 - 9205

Опубликована: Июль 12, 2019

Hydroalkylation of unsaturated hydrocarbons with unstabilized carbon nucleophiles is difficult and remains a major challenge. The disclosed examples so far have mainly focused on the involvement heteroatom and/or stabilized as efficient reaction partners. Reported here an unprecedented regioselective nickel-catalyzed hydrobenzylation 1,3-dienes hydrazones, generated in situ from abundant aryl aldehydes ketones acting both sources carbanion equivalent hydride. With this strategy, terminal sterically hindered internal dienes are hydroalkylated efficiently highly selective manner, thus providing reliable catalytic method to construct challenging C(sp3)–C(sp3) bonds.

Язык: Английский

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Acceptorless Dehydrogenative Coupling Reactions by Manganese Pincer Complexes

Asian Journal of Organic Chemistry, Год журнала: 2021, Номер 10(8), С. 1958 - 1985

Опубликована: Май 26, 2021

Abstract Acceptorless dehydrogenative coupling reactions has emerged as one of the promising technique in synthetic organic chemistry to construct carbon‐carbon and carbon‐heteroatom bonds an environmentally benign sustainable way. The methodology is highly atom economical produces water hydrogen byproducts. This protocol, coupled with earth‐abundant less toxic manganese catalyst provides a unique opportunity various synthons biologically important motifs. In recent years, tremendous progress been made catalysis based on pincer ligands for homogeneous transformations. review covers field catalyzed acceptorless reactions, their scope brief mechanistic discussion.

Язык: Английский

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