Phosphonium-Catalyzed Monoreduction of Bisphosphine Dioxides: Origin of Selectivity and Synthetic Applications

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(13), P. 9335 - 9346

Published: March 19, 2024

Controlling product selectivity in successive reactions of the same type is challenging owing to comparable thermodynamic and kinetic properties involved. Here, synergistic interaction two phosphoryl groups bisphosphine dioxides (BPDOs) with a bromo-phosphonium cation was studied experimentally provide practical tool for substrate–catalyst recognition. As eventual result, we have developed phosphonium-catalyzed monoreduction chiral BPDOs access an array synthetically useful monoxides (BPMOs) axial, spiro, planar chirality, which are otherwise synthesize before. The reaction features excellent impressive reactivity. It proceeds under mild conditions, avoiding use superstoichiometric amounts additives metal catalysts simplify synthetic procedure. accessibility scalability allowed rapid construction ligand library optimization asymmetric Heck-type cyclization, laying foundation broad range applications BPMOs catalysis.

Language: Английский

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Combined Computational and Experimental Study Reveals Complex Mechanistic Landscape of Brønsted Acid-Catalyzed Silane-Dependent P═O Reduction

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(20), P. 13983 - 13999

Published: May 13, 2024

The reaction mechanism of Brønsted acid-catalyzed silane-dependent P═O reduction has been elucidated through combined computational and experimental methods. Due to its remarkable chemo- stereoselective nature, the acid/silane system widely employed in organophosphine-catalyzed transformations involving P(V)/P(III) redox cycle. However, full mechanistic profile this type yet be clearly established date. Supported by both DFT studies, our research reveals that likely proceeds mechanisms other than accepted "dual activation mode silyl ester" or "acid-mediated direct activation" mechanism. We propose although may vary with substitution patterns silane species, acid generally activates rather group transition structures. proposed differs significantly from associated traditional C═O reduction. uniqueness originates dominant Si/O═P orbital interactions structures P/H–Si interactions. comprehensive landscape provided us will serve as a guidance for rational design development more efficient systems well novel reactions

Language: Английский

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Rapid Synthesis of Peptides Mediated by PPh₃−I₂

Asian Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 13(8)

Published: April 24, 2024

Abstract We report a mild, operationally simple, convenient, and rapid method of peptide bond formation using triphenylphosphine iodine. The developed protocol was utilized to couple coded, non‐coded, challenging amino acids in 64–92 % yield. Sterically hindered α,α‐disubstituted acids, which are important constituents natural peptides, were also coupled good Mild reaction conditions open air produce bonds short time (30 min) without racemization.

Language: Английский

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Improved Electrochemical Peptide Synthesis Enabled by Electron‐Rich Triaryl Phosphines

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: unknown

Published: July 10, 2024

Abstract While remarkable progress has been made in the development of peptide medicines, many problems related to synthesis remain unresolved. Previously, we reported electrochemical using a phosphine as potentially recyclable coupling reagent. However, there was room for improvement from point view reaction efficiency, especially carboxylic acid activation step and bond formation step. To overcome these challenges, searched optimal phosphine. Among phosphines with various electronic properties, found that electron‐rich triaryl improved efficiency. Consequently, successfully performed on sterically hindered valuable amino acids. We also synthesized oligopeptides were challenging our previous method. Finally, examined effect substituents cations, gained some insights into reactivity, which will aid researchers designing reactions involving cations.

Language: Английский

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Diverse Catalytic Applications of Phosphine Oxide‐Based Metal Complexes

ChemCatChem, Journal Year: 2024, Volume and Issue: 16(22)

Published: Aug. 17, 2024

Abstract Phosphine oxides are an interesting class of compounds possessing tetracoordinate and pentavalent phosphorus atoms have been employed in a wide range applications including reagents organic synthesis, metal extractants, flame retardants, pharmaceuticals, bioactivity studies. Among all, the degree basicity phosphoryl oxygen driven by nature substituents influences electronic properties central complex toward diversified catalytic processes. Further, presence heteroatoms adjacent to atom enhances nucleophilicity atom. In view this, present review covers past two decades remarkable versatility P=O‐based complexes describes governing factors influencing structural resultant coordination behavior. Interestingly, some P=O bond distances either longer or shorter compared their free ligands, indicating activity. These can effectively catalyze chemical reactions polymerizations, C−C Si−C activations, oxidation, reduction, hydroformylation, hydrophosphination, hydrogenation cyclization reactions. Furthermore, this emphasizes impact substituents, solvents, additives, light, temperature on efficiency.

Language: Английский

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Theoretical Mechanism Study of BH3‐Mediated Reduction of P‐Stereogenic Hydroxyalkylphosphine Oxides

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: June 3, 2024

Abstract The BH 3 ‐mediated reduction of P‐stereogenic hydroxyalkylphosphine oxides was investigated by Density Functional Theory calculations. By combining theoretical approaches with experimental observations, we explored two mechanisms that account for its stereospecificity, implying an inversion the configuration at phosphorus atom. One mechanism proceeds through a cyclic intermediate in which coordination borane to oxygen atoms lowers .THF‐attack barrier. However, free energy barrier this combined process is too high reaction feasible room temperature. calculations rather support second from same and in‐situ formation 4 − as reducing agent.

Language: Английский

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Auto‐Optimized Electro‐Flow Reactor Platform for the in‐situ Reduction of P(V) Oxide to P(III) and Their Application

Chemistry - An Asian Journal, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 11, 2024

Abstract Trivalent phosphine catalysis is mostly utilized to activate the carbon‐carbon multiple bonds form carbanion intermediate species and highly sensitive certain variables. Random manual multi‐variables are critical for understanding batch disabled regeneration of trivalent chemistry. We need artificial intelligence‐based system which can change variable based on previously conducted failed experiment. Herein, we report an auto‐optimized electro‐micro‐flow reactor platform in‐situ reduction stable P(V) oxide P(III) further method Corey‐Fuchs reaction.

Language: Английский

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