Enantioselective Hydrogenation of Tetrasubstituted α,β‐Unsaturated Carboxylic Acids Enabled by Cobalt(II) Catalysis: Scope and Mechanistic Insights

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(20), С. 11384 - 11390

Опубликована: Фев. 19, 2021

Abstract Chiral carboxylic acids are important compounds because of their prevalence in pharmaceuticals, natural products and agrochemicals. Asymmetric hydrogenation α,β‐unsaturated has been widely recognized as one the most efficient synthetic approaches to afford such compounds. Although related asymmetric di‐ trisubstituted unsaturated with noble metals is well established, challenging tetrasubstituted rarely reported. We demonstrate enantioselective cyclic acyclic via cobalt(II) catalysis. This protocol showed broad substrate scope gave chiral good yields excellent enantiocontrol (up 98 % yield 99 ee ). Combined experimental computational mechanistic studies support a Co II catalytic cycle involving migratory insertion σ‐bond metathesis processes. DFT calculations reveal that enantioselectivity may originate from steric effect between phenyl groups ligand substrate.

Язык: Английский

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Cobalt‐Catalyzed Chemo‐ and Enantioselective Hydrogenation of Conjugated Enynes

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(31), С. 16989 - 16993

Опубликована: Июнь 1, 2021

Asymmetric hydrogenation is one of the most powerful methods for preparation single enantiomer compounds. However, chemo- and enantioselective relatively inert unsaturated group in substrates possessing multiple bonds remains a challenge. We herein report protocol highly conjugated enynes while keeping alkynyl bond intact. Mechanism studies indicate that accompanying Zn2+ generated from zinc reduction CoII complex plays critical role to initiate plausible CoI /CoIII catalytic cycle. This approach allows efficient generation chiral propargylamines (up 99.9 % ee 2000 S/C) further useful chemical transformations.

Язык: Английский

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Manganese‐Catalyzed Asymmetric Hydrogenation of 3H‐Indoles

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(20)

Опубликована: Март 3, 2022

The asymmetric hydrogenation (AH) of 3H-indoles represents an ideal approach to the synthesis useful chiral indoline scaffolds. However, very few catalytic systems based on precious metals have been developed realize this challenging reaction. Herein, we report a Mn-catalyzed AH with excellent yields and enantioselectivities. kinetic resolution racemic by was also achieved high s-factors construct quaternary stereocenters. Many acid-sensitive functional groups, which cannot be tolerated when using state-of-the-art ruthenium catalyst, were compatible manganese catalysis. This new process expands scope transformation highlights uniqueness earth-abundant metal reaction could proceed catalyst loadings at parts per million (ppm) level exceptional turnover number 72 350. is highest value yet reported for metal-catalyzed

Язык: Английский

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Manganese‐Catalyzed Asymmetric Formal Hydroamination of Allylic Alcohols: A Remarkable Macrocyclic Ligand Effect

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(26)

Опубликована: Апрель 19, 2022

A unique family of chiral peraza N6 -macrocyclic ligands, which are conformationally rigid and have a tunable saddle-shaped cavity, is described. Utilizing their manganese(I) complexes, the first example earth-abundant transition metal-catalyzed asymmetric formal anti-Markovnikov hydroamination allylic alcohols was realized, providing practical access to synthetically important γ-amino in excellent yields enantioselectivities (up 99 % yield 98 ee). The single-crystal structure MnI complex indicates that manganese atom coordinates with dialkylamine moiety bidentate fashion. Further DFT calculations revealed five six nitrogen atoms ligand were engaged multiple noncovalent interactions Mn, an isopropanol molecule, β-amino ketone intermediate via coordination, hydrogen bonding, and/or CH⋅⋅⋅π state, showing remarkable role macrocyclic framework.

Язык: Английский

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Nickel‐Catalyzed Asymmetric Hydrogenation of α‐Substituted Vinylphosphonates and Diarylvinylphosphine Oxides

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(6)

Опубликована: Дек. 12, 2022

Chiral α-substituted ethylphosphonate and ethylphosphine oxide compounds are widely used in drugs, pesticides, ligands. However, their catalytic asymmetric synthesis is still rare. Of the only hydrogenation methods available at present, all cases use rare metal catalysts. Herein, we report an efficient earth-abundant transition-metal nickel catalyzed affording corresponding chiral products with up to 99 % yield, 96 ee (enantiomeric excess) (99 ee, after recrystallization) 1000 S/C (substrate/catalyst); this also first study on of terminal olefins using a catalyst under hydrogen atmosphere. The mechanism was investigated via deuterium-labelling experiments calculations which indicate that two added atoms come from gas. Additionally, it believed reaction involves NiII rather than Ni0 cyclic process based weak attractive interactions between Ni olefin substrate.

Язык: Английский

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Rational Design of a Facially CoordinatingP,N,NLigand for Manganese‐Catalysed Enantioselective Hydrogenation of Cyclic Ketones

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(3)

Опубликована: Ноя. 7, 2022

DFT calculations on the full catalytic cycle for manganese catalysed enantioselective hydrogenation of a selection ketones have been carried out at PBE0-D3

Язык: Английский

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Precise Synthesis of ChiralZ‐Allylamides by Cobalt‐Catalyzed Asymmetric Sequential Hydrogenations

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(15)

Опубликована: Фев. 8, 2023

Asymmetric sequential hydrogenations of conjugated enynes have been developed using a Ph-BPE-CoI catalyst for the precise synthesis chiral Z-allylamides in high activity (up to 1000 substrate/catalyst (S/C)) and with excellent enantioselectivity >99 % enantiomeric excess (ee)). Mechanism experiments theoretical calculations support cationic CoI /CoIII redox catalytic cycle. The difference between cobalt complexes Ph-BPE QuinoxP* was explained by process decomposition rate-determining step second hydrogenation.

Язык: Английский

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Efficient Hydrogenation of N‐Heterocycles Catalyzed by NNP–Manganese(I) Pincer Complexes at Ambient Temperature

Chemistry - A European Journal, Год журнала: 2022, Номер 29(2)

Опубликована: Окт. 4, 2022

Manganese-catalyzed hydrogenation reactions have aroused widespread interest in recent years. Among the catalytic systems described, especially PNP- and NNP-Mn pincer catalysts been reported for of aldehydes, ketones, nitriles, aldimines esters. Furthermore, compounds are efficient hydrogenolysis less reactive amides, ureas, carbonates, carbamates. Herein, synthesis application specific imidazolylaminophosphine ligands corresponding Mn complexes described. These new characterized studied by a combination experimental theoretical investigations, their activities tested several with good to excellent performance. Especially, reduction N-heterocycles can be performed under very mild conditions.

Язык: Английский

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Simultaneous Kinetic Resolution and Asymmetric Induction within a Borrowing Hydrogen Cascade Mediated by a Single Catalyst

Angewandte Chemie International Edition, Год журнала: 2021, Номер 61(3)

Опубликована: Окт. 9, 2021

Abstract The mechanistic uniqueness and versatility of borrowing hydrogen catalysis provides an opportunity to investigate the controllability a cascade reaction, more importantly, realize either one or both chiral recognition induction simultaneously. Here we report that, in starting from racemic allylic alcohols, enantiomers could be kinetically resolved, while other enantiomer purposely converted various targeted products, including α,β‐unsaturated ketones, β‐functionalized ketones γ‐functionalized alcohols. By employing robust Ru‐catalyst, kinetic resolution asymmetric were achieved with remarkable levels efficiency enantioselectivity. Density functional theory (DFT) calculations suggest that corresponding catalyst–substrate π–π interactions are pivotal observed stereochemical diversity.

Язык: Английский

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Manganese‐Catalyzed Asymmetric Formal Hydroamination of Allylic Alcohols: A Remarkable Macrocyclic Ligand Effect

Angewandte Chemie, Год журнала: 2022, Номер 134(26)

Опубликована: Апрель 19, 2022

Abstract A unique family of chiral peraza N 6 ‐macrocyclic ligands, which are conformationally rigid and have a tunable saddle‐shaped cavity, is described. Utilizing their manganese(I) complexes, the first example earth‐abundant transition metal‐catalyzed asymmetric formal anti‐Markovnikov hydroamination allylic alcohols was realized, providing practical access to synthetically important γ‐amino in excellent yields enantioselectivities (up 99 % yield 98 ee). The single‐crystal structure Mn I complex indicates that manganese atom coordinates with dialkylamine moiety bidentate fashion. Further DFT calculations revealed five six nitrogen atoms ligand were engaged multiple noncovalent interactions Mn, an isopropanol molecule, β‐amino ketone intermediate via coordination, hydrogen bonding, and/or CH⋅⋅⋅π state, showing remarkable role macrocyclic framework.

Язык: Английский

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