Borrowing Hydrogen for Organic Synthesis

ACS Central Science, Год журнала: 2021, Номер 7(4), С. 570 - 585

Опубликована: Март 25, 2021

Borrowing hydrogen is a process that used to diversify the synthetic utility of commodity alcohols. A catalyst first oxidizes an alcohol by removing form reactive carbonyl compound. This intermediate can undergo diverse range subsequent transformations before returns "borrowed" liberate product and regenerate catalyst. In this way, alcohols may be as alkylating agents whereby sole byproduct one-pot reaction water. recent decades, significant advances have been made in area, demonstrating many effective methods access valuable products. outlook highlights diversity metal biocatalysts are available for approach, well various performed, focusing on selection most advances. By succinctly describing conveying versatility borrowing chemistry, we anticipate its uptake will increase across wider scientific audience, expanding opportunities further development.

Язык: Английский

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Manganese-catalyzed hydrogenation, dehydrogenation, and hydroelementation reactions

Chemical Society Reviews, Год журнала: 2022, Номер 51(11), С. 4386 - 4464

Опубликована: Янв. 1, 2022

The emerging field of organometallic catalysis has shifted towards research on Earth-abundant transition metals due to their ready availability, economic advantage, and novel properties. In this case, manganese, the third most abundant transition-metal in Earth's crust, emerged as one leading competitors. Accordingly, a large number molecularly-defined Mn-complexes been synthesized employed for hydrogenation, dehydrogenation, hydroelementation reactions. regard, catalyst design is based three pillars, namely, metal-ligand bifunctionality, ligand hemilability, redox activity. Indeed, developed catalysts not only differ chelating atoms they possess but also working principles, thereby different turnover numbers product molecules. Hence, critical assessment molecularly defined manganese terms atoms, reaction conditions, mechanistic pathway, significant. Herein, we analyze complexes catalytic activity, versatility allow multiple transformations routes convert substrates target This article will be helpful get significant insight into design, aiding design.

Язык: Английский

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Alcohols as Substrates in Transition-Metal-Catalyzed Arylation, Alkylation, and Related Reactions

Chemical Reviews, Год журнала: 2024, Номер 124(9), С. 6078 - 6144

Опубликована: Апрель 17, 2024

Alcohols are abundant and attractive feedstock molecules for organic synthesis. Many methods their functionalization require them to first be converted into a more activated derivative, while recent years have seen vast increase in the number of complexity-building transformations that directly harness unprotected alcohols. This Review discusses how transition metal catalysis can used toward this goal. These broadly classified three categories. Deoxygenative functionalizations, representing derivatization C–O bond, enable alcohol act as leaving group formation new C–C bonds. Etherifications, characterized by O–H represent classical reactivity has been modernized include mild reaction conditions, diverse partners, high selectivities. Lastly, chain reactions described, wherein acts mediator formal C–H alkyl backbone. Each these classes transformation will discussed context intermolecular arylation, alkylation, related reactions, illustrating alcohols harnessed

Язык: Английский

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Phosphine-Free Manganese Catalyst Enables Selective Transfer Hydrogenation of Nitriles to Primary and Secondary Amines Using Ammonia–Borane

ACS Catalysis, Год журнала: 2021, Номер 11(5), С. 2786 - 2794

Опубликована: Фев. 15, 2021

Herein we report the synthesis of primary and secondary amines by nitrile hydrogenation, employing a borrowing hydrogenation strategy. A class phosphine-free manganese(I) complexes bearing sulfur side arms catalyzed reaction under mild conditions, where ammonia–borane is used as source hydrogen. The synthetic protocol chemodivergent, final product either or amine, which can be controlled changing catalyst structure polarity medium. significant advantage this method that operates without externally added base other additives well obviates use high-pressure dihydrogen gas required for reactions. Utilizing method, wide variety symmetric asymmetric were synthesized in high yields. mechanistic study involving kinetic experiments high-level DFT computations revealed both outer-sphere dehydrogenation inner-sphere predominantly operative catalytic cycle.

Язык: Английский

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Advancements in multifunctional manganese complexes for catalytic hydrogen transfer reactions

Chemical Communications, Год журнала: 2021, Номер 57(69), С. 8534 - 8549

Опубликована: Янв. 1, 2021

Manganese catalyzed hydrogen transfer reactions enabled net reductions and cascade CC- CN-bond formation reactions. The success is aided by multifunctional ligand design namely metal–ligand bifunctionality, hemilability, redox non-innocence.

Язык: Английский

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Selective Catalytic Synthesis of α-Alkylated Ketones and β-Disubstituted Ketones via Acceptorless Dehydrogenative Cross-Coupling of Alcohols

Organic Letters, Год журнала: 2021, Номер 23(3), С. 869 - 875

Опубликована: Янв. 21, 2021

Herein, a phosphine-free pincer ruthenium(III) catalyzed β-alkylation of secondary alcohols with primary to α-alkylated ketones and two different β-branched are reported. Notably, this transformation is environmentally benign atom efficient H2O H2 gas as the only byproducts. The protocol extended gram-scale reaction for functionalization complex vitamin E cholesterol derivatives.

Язык: Английский

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Towards ligand simplification in manganese-catalyzed hydrogenation and hydrosilylation processes

Coordination Chemistry Reviews, Год журнала: 2022, Номер 458, С. 214421 - 214421

Опубликована: Янв. 31, 2022

Язык: Английский

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Divergent Synthesis of Alcohols and Ketones via Cross‐Coupling of Secondary Alcohols under Manganese Catalysis

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(26)

Опубликована: Апрель 21, 2023

A homogeneous manganese-catalyzed cross-coupling of two secondary alcohols for the divergent synthesis γ-disubstituted and β-disubstituted ketones is reported. Employing well-defined Mn-MACHOPh as catalyst, this novel protocol has a broad substrate scope with good functional group tolerance affords diverse library valuable disubstituted in moderate to yields. The strong influence reaction temperature on selective formation alcohol products was theorized preliminary DFT studies. Studies have shown that Gibbs free energy thermodynamically more favourable than corresponding at lower temperature.

Язык: Английский

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Recent advances and emerging opportunities in mechanism and applications of earth abundant manganese-catalysts for sustainable organic transformations

Journal of Organometallic Chemistry, Год журнала: 2024, Номер 1009, С. 123071 - 123071

Опубликована: Фев. 23, 2024

Язык: Английский

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Manganese-Catalyzed Anti-Markovnikov Hydroamination of Allyl Alcohols via Hydrogen-Borrowing Catalysis

ACS Catalysis, Год журнала: 2021, Номер 11(12), С. 7060 - 7069

Опубликована: Июнь 2, 2021

Controlling the selectivity in a hydroamination reaction is an extremely challenging yet highly desirable task for diversification of amines. In this article, selective formal anti-Markovnikov allyl alcohols presented. It enables versatile synthesis valuable γ-amino alcohol building blocks. A phosphine-free Earth's abundant manganese(I) complex catalyzed under hydrogen-borrowing conditions. vast range aliphatic, aromatic amines, drug molecules, and natural product derivatives underwent successful with primary secondary allylic excellent functional group tolerance (57 examples). The catalysis could be performed on gram scale has been applied molecules. mechanistic studies revealed metal–ligand bifunctionality as well hemilability ligand backbone key design principle success catalysis.

Язык: Английский

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