Bimetallic Catalysis in Stereodivergent Synthesis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(45)

Published: Aug. 2, 2022

Abstract Bimetallic catalysis has emerged as an efficient strategy for the development of new chemical reactions. Importantly, this also provides a simple and powerful platform stereodivergent synthesis, whereby all possible stereoisomers products bearing two stereocenters can be easily prepared from same set starting materials. In Minireview, allylic substitution, propargylic hydrofunctionalization, annulation based on bimetallic been summarized. It is expected that more catalytic systems will developed applied synthesis valuable molecules.

Language: Английский

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Electrosynthesis of amino acids from NO and α-keto acids using two decoupled flow reactors

Nature Catalysis, Journal Year: 2023, Volume and Issue: 6(10), P. 906 - 915

Published: Aug. 21, 2023

Language: Английский

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Catalytic Asymmetric Hydroalkoxylation and Formal Hydration and Hydroaminoxylation of Conjugated Dienes

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(7), P. 3915 - 3925

Published: Feb. 10, 2023

The straightforward construction of stereogenic centers bearing unprotected functional groups, as in nature, has been a persistent pursuit synthetic chemistry. Abundant applications free enantioenriched allyl alcohol and hydroxylamine motifs have made the asymmetric hydration hydroaminoxylation conjugated dienes from water hydroxylamine, respectively, intriguing efficient routes that have, however, unachievable thus far. A fundamental challenge is failure to realize transition-metal-catalyzed enantioselective C–O bond constructions via hydrofunctionalization dienes. Here, we perform comprehensive study toward stereoselective formal by synthesizing set new P,N-ligands identifying an aryl-derived oxime surrogate for both hydroxylamine. Asymmetric hydroalkoxylation with also elucidated. Furthermore, versatile derivatizations following provide indirect but concise hydrophenoxylation, hydrofluoroalkoxylation, hydrocarboxylation unreported Finally, ligand-to-ligand hydrogen transfer process proposed based on results preliminary mechanistic experiments.

Language: Английский

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Catalyst Selection over an Electrochemical Reductive Coupling Reaction toward Direct Electrosynthesis of Oxime from NO_x and Aldehyde

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(9), P. 6294 - 6306

Published: Feb. 20, 2024

Aqueous electrochemical coupling reactions, which enable the green synthesis of complex organic compounds, will be a crucial tool in synthetic chemistry. However, lack informed approaches for screening suitable catalysts is major obstacle to its development. Here, we propose pioneering reductive reaction toward direct electrosynthesis oxime from NOx and aldehyde. Through integrating experimental theoretical methods, screen out optimal catalyst, i.e., metal Fe that facilitates enrichment C–N key intermediates, all leading high yields (e.g., ∼99% yield benzaldoxime) over Fe. With divided flow reactor, achieve benzaldoxime production 22.8 g h–1 gcat–1 ∼94% isolated yield. This work not only paves way industrial mass via but also offers references catalyst selection other reactions.

Language: Английский

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Asymmetric hydrogenation of ketimines with minimally different alkyl groups

Nature, Journal Year: 2024, Volume and Issue: 631(8021), P. 556 - 562

Published: May 28, 2024

Language: Английский

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Synthesis of Hydroxylamine via Ketone-Mediated Nitrate Electroreduction

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(15), P. 10934 - 10942

Published: April 6, 2024

Hydroxylamine (HA, NH2OH) is a critical feedstock in the production of various chemicals and materials, its efficient sustainable synthesis great importance. Electroreduction nitrate on Cu-based catalysts has emerged as promising approach for green ammonia (NH3) production, but electrosynthesis HA remains challenging due to overreduction NH3. Herein, we report first work ketone-mediated using water. A metal–organic-framework-derived Cu catalyst was developed catalyze reaction. Cyclopentanone (CP) used capture situ form CP oxime (CP-O) with C═N bonds, which prone hydrolysis. could be released easily after electrolysis, regenerated. It demonstrated that CP-O formed an excellent Faradaic efficiency 47.8%, corresponding formation rate 34.9 mg h–1 cm–2, remarkable carbon selectivity >99.9%. The hydrolysis release regeneration also optimized, resulting 96.1 mmol L–1 stabilized solution, significantly higher than direct reduction. Detailed characterizations, control experiments, theoretical calculations revealed surface reconstruction reaction mechanism, showed coexistence Cu0 Cu+ facilitated protonation reduction *NO2 *NH2OH desorption, leading enhancement production.

Language: Английский

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Synergistic Pd/Cu-Catalyzed 1,5-Double Chiral Inductions

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(13), P. 9241 - 9251

Published: March 19, 2024

Much attention has been focused on the catalytic asymmetric creation of single chiral centers or two adjacent stereocenters. However, construction nonadjacent stereocenters is significant importance but challenging because lack remote induction models. Herein, based a C═C bond relay strategy, we report synergistic Pd/Cu-catalyzed 1,5-double model. All four stereoisomers target products bearing 1,5-nonadjacent involving both allenyl axial and central chirality could be obtained divergently by simply changing combination catalysts with different configurations. Control experiments DFT calculations reveal novel mechanism 1,5-oxidative addition, contra-thermodynamic η3-allyl palladium shift, conjugate nucleophilic substitution, which play crucial roles in control reactivity, regio-, enantio-, diastereoselectivity. It expected that this strategy may provide general protocol for synthesis structural motifs distant

Language: Английский

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A 13-million turnover-number anionic Ir-catalyst for a selective industrial route to chiral nicotine

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: June 22, 2023

Abstract Developing catalysts with both useful enantioselectivities and million turnover numbers (TONs) for asymmetric hydrogenation of ketones is attractive industrial production high-value bioactive chiral entities but remains a challenging. Herein , we report an ultra-efficient anionic Ir-catalyst integrated the concept multidentate ligation ketones. Biocatalysis-like efficacy up to 99% ee (enantiomeric excess), 13,425,000 TON (turnover number) 224 s −1 TOF frequency) were documented benchmark acetophenone. Up 1,000,000 achieved challenging pyridyl alkyl ketone where at most 10,000 TONs are previously reported. The showed novel preferred ONa/MH instead NNa/MH bifunctional mechanism. A selective route enantiopure nicotine has been established using this key step 500 kg batch scale, providing 40 tons scale product.

Language: Английский

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Descriptor‐Based Volcano Relations Predict Single Atoms for Hydroxylamine Electrosynthesis

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(14)

Published: Feb. 7, 2024

Abstract Hydroxylamine (NH 2 OH) is an important feedstock in fuels, pharmaceuticals, and agrochemicals. Nanostructured electrocatalysts drive green electrosynthesis of hydroxylamine from nitrogen oxide species water. However, current still suffer low selectivity manpower‐consuming trial‐and‐error modes, leaving unclear selectivity/activity origins a lack catalyst design principles. Herein, we theoretically analyze key determinants propose the adsorption energy NHO ( G ad (*NHO)) as performance descriptor. A weak *NH OH binding affinity favorable reaction pathway (*NHO pathway) jointly enable single‐atom catalysts (SACs) with superior NH selectivity. Then, activity volcano plot (*NHO) established to predict series SACs discover Mn optimal that exhibit pH‐dependent activity. These theoretical prediction results are also confirmed by experimental results, rationalizing our Furthermore, Mn−Co geminal‐atom (GACs) predicted optimize experimentally proved enhance formation.

Language: Английский

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Challenging Task of Ni-Catalyzed Highly Regio-/Enantioselective Semihydrogenation of Racemic Tetrasubstituted Allenes via a Kinetic Resolution Process

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(11), P. 7419 - 7430

Published: March 6, 2024

The first earth-abundant transition metal Ni-catalyzed highly regio- and enantioselective semihydrogenation of racemic tetrasubstituted allenes via a kinetic resolution process as challenging task was well established. This protocol furnishes expedient access to diversity structurally important enantioenriched chiral allylic molecules with high regio-, enantio-, Z/E-selectivity. Remarkably, this proceeded one carbon–carbon double bond allenes, which regioselective complementary the Rh-catalyzed asymmetric version. Deuterium labeling experiments density functional theory (DFT) calculations were carried out reveal reasonable reaction mechanism explain regio-/stereoselectivity.

Language: Английский

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