Chalcogen Bonding Catalysis with Phosphonium Chalcogenide (PCH)

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(5), P. 608 - 621

Published: Feb. 20, 2023

ConspectusThe exploration of new catalysis concepts and strategies to drive chemical reactions is vital importance for the sustainable development organic synthesis. Recently, chalcogen bonding has emerged as a concept synthesis been demonstrated be an important synthetic tool capable addressing elusive reactivity selectivity issues. This Account describes our progress in research field catalysis, including (1) discovery phosphonium chalcogenide (PCH) highly efficient catalyst; (2) "chalcogen-chalcogen catalysis" "chalcogen···π modes; (3) demonstration that with PCH can activate hydrocarbons achieve cyclization coupling alkenes; (4) unusual results solve issues are inaccessible by classic approaches; (5) elucidation mechanisms.With catalysts, we systematically studied their properties, relationship between structure application facilitating diverse array reactions. Enabled chalcogen-chalcogen assembly reaction three molecules β-ketoaldehyde one indole derivative single operation was realized, delivering heterocycles newly constructed seven-membered ring. In addition, Se···O approach achieved calix[4]pyrroles. We developed "dual strategy Rauhut-Currier-type related cascade cyclizations, thus shifting conventionally covalent Lewis base cooperative approach. enables cyanosilylation ketones take place presence ppm-level amount catalyst loading. Furthermore, established chalcogen···π catalytic transformation alkenes. supramolecular activation such alkenes weak interactions interesting unresolved topic. showed Se···π could efficiently both Chalcogen···π catalysts particularly highlighted capability strong Lewis-acid transformations, controlled cross triple Overall, this presents panoramic view on catalysts. The works described provide significant platform problems.

Language: Английский

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Halogen, Chalcogen, Pnictogen, and Tetrel Bonding in Non‐Covalent Organocatalysis: An Update

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(31)

Published: May 11, 2024

The use of noncovalent interactions based on electrophilic halogen, chalcogen, pnictogen, or tetrel centers in organocatalysis has gained noticeable attention. Herein, we provide an overview the most important developments last years with a clear focus experimental studies and catalysts which act via such non-transient interactions.

Language: Английский

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Control of Selectivity in Homogeneous Catalysis through Noncovalent Interactions

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(26)

Published: Feb. 23, 2023

The regio-, site-, stereo- or chemoselective homogeneous catalytic transformations are extremely important for the growth/success of current chemical industry. Based on empirical, theoretical intuitive knowledge, several synthetic strategies, such as ligand design, transient directing group, metal node alternation, metal-ligand cooperation, pore decoration, biomimetic, have already been developed selective functionalization organic substrates. In comparison to other tactics, use noncovalent interactions control selectivity in compounds may avoid multi-steps, reduce time procedure, decrease cost operation, and increase reactivity catalyst. fact, enzymes achieve a high through biochemical processes Nature. Guided by impressive performance biosynthesis biodegradation reactions, various types complex organocatalysts developed, which catalyst-substrate pivotal impact distinctive stabilization transition states intermediates, improving efficiency reactions. Herein, we highlight recent relevant examples directing/driving function transformation substrate(s) catalyzed both catalysts.

Language: Английский

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Harnessing Multistep Chalcogen Bonding Activation in the α-Stereoselective Synthesis of Iminoglycosides

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(15), P. 10608 - 10620

Published: April 2, 2024

The use of noncovalent interactions (NCIs) has received significant attention as a pivotal synthetic handle. Recently, the exploitation unconventional NCIs gained considerable traction in challenging reaction manifolds such glycosylation due to their capacity facilitate entry into difficult-to-access sugars and glycomimetics. While investigations involving oxacyclic pyrano- or furanoside scaffolds are relatively common, methods that allow selective synthesis biologically important iminosugars comparatively rare. Here, we report phosphonochalcogenide (PCH) catalyze stereoselective α-iminoglycosylation iminoglycals with wide array glycosyl acceptors remarkable protecting group tolerance. Mechanistic studies have illuminated counterintuitive role catalyst serially activating both donor acceptor up/downstream stages through chalcogen bonding (ChB). dynamic interaction chalcogens substrates opens up new mechanistic opportunities based on iterative ChB engagement disengagement multiple elementary steps.

Language: Английский

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A Hexavalent Tellurium-Based Chalcogen Bonding Catalysis Platform: High Catalytic Activity and Controlling of Selectivity

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 13, 2025

Herein, we describe a hexavalent tellurium-based chalcogen bonding catalysis platform capable of addressing reactivity and selectivity issues. This research demonstrates that tellurium salts can serve as class highly active catalysts for the first time. The centers in these have only one exposed interaction site, thus providing favorable condition controlling reaction selectivity. advantages were demonstrated by their remarkable catalytic activity cyanidation difluorocyclopropenes through C-F bond activation, which otherwise low reactive under strong Lewis acids or inaccessible representative divalent/tetravalent donors. catalyst was further highlighted its capability to address previously unresolved problem associated with acid approach, upon using some less silyl enol ethers nucleophiles functionalization difluorocyclopropenes. generality this versatile application different systems. differentiate two similar free OH groups glycosyl acceptors achieve excellent regio- stereoselectivity synthesis disaccharides, tetravalent gave Mechanistic investigation suggests catalyst-glycosyl donor-acceptor ternary supramolecular complex is operative.

Language: Английский

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Neutral Chalcogen Bonding Enabled Photoinduced Cross‐Electrophile C—S/Se Coupling of Aryl Iodides via S_RN1 Process

Chinese Journal of Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 7, 2025

Comprehensive Summary Cross‐coupling reactions between aryl halides and thiolates or selenolates typically require transition metals, photocatalysts, strong bases, or/and malodorous thiols/selenols, with various mechanisms proposed. This study aims to leverage a new application of neutral ChB address these challenges enable very simple photoinduced cross‐electrophile C—S/Se coupling using readily available chalcogen electrophiles. Mechanistic investigations have revealed the important role in facilitating single electron transfer processes, thereby enabling generation thiolates/selenolates from stable electrophiles α ‐aminoalkyl radicals, which possess capability abstract halogen atoms iodides. Moreover, provided support for radical nucleophilic substitution mechanism.

Language: Английский

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Cooperative Bifurcated Chalcogen Bonding and Hydrogen Bonding as Stereocontrolling Elements for Selective Strain-Release Septanosylation

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(49), P. 26611 - 26622

Published: Nov. 30, 2023

The exploitation of noncovalent interactions (NCIs) is emerging as a vital handle in tackling broad stereoselectivity challenges synthesis. In particular, there has been significant recent interest the harnessing unconventional NCIs to surmount difficult selectivity glycosylations. Herein, we disclose an bifurcated chalcogen bonding and hydrogen (HB) network, which paves way for robust catalytic strategy into biologically useful seven-membered ring sugars. Through 13C nuclear magnetic resonance (NMR) situ monitoring, NMR titration experiments, density functional theory (DFT) modeling, propose remarkable contemporaneous activation multiple groups consisting mechanism working hand-in-hand with HB activation. Significantly, ester moiety installed on glycosyl donor critical establishment postulated ternary complex stereocontrol. kinetic isotopic effect studies, our data corroborated that dissociative SNi-type forms stereocontrolling basis excellent α-selectivity.

Language: Английский

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Exploiting π and Chalcogen Interactions for the β‐Selective Glycosylation of Indoles through Glycal Conformational Distortion

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(7)

Published: Dec. 20, 2023

Harnessing unconventional noncovalent interactions (NCIs) is emerging as a formidable synthetic approach in difficult-to-access glycosidic chemical space. C-Glycosylation, particular, has gained flurry of recent attention. However, most reported methods are restricted to the relatively facile access α-C-glycosides. Herein, we disclose β-stereoselective glycosylation indoles by employing phosphonoselenide catalyst. The robustness this protocol exemplified its amenability for reaction at both indolyl C- and N- reactivity sites. In contrast previous reports, which chalcogens were solely involved Lewis acidic activation, our mechanistic investigation unraveled that often neglected flanking aromatic substituents phosphonoselenides can substantially contribute catalysis engaging π-interactions. Computations NMR spectroscopy indicated chalcogenic components catalyst be collectively exploited foster conformational distortion glycal away from usual half-chair boat conformation, liberates convex β-face nucleophilic attack.

Language: Английский

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Stereoselective Entry into α,α’‐C‐Oxepane Scaffolds through a Chalcogen Bonding Catalyzed Strain‐Release C‐Septanosylation Strategy

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(29)

Published: April 30, 2024

Abstract The utility of unconventional noncovalent interactions (NCIs) such as chalcogen bonding has lately emerged a robust platform to access synthetically difficult glycosides stereoselectively. Herein, we disclose the versatility phosphonochalcogenide (PCH) catalyst facilitate into challenging, but biologically interesting 7‐membered ring α,α’‐ C ‐disubstituted oxepane core through an α‐selective strain‐release ‐glycosylation. Methodically, this strategy represents switch from more common entropically less desired macrocyclizations thermodynamically favored ring‐expansion approach. In light general lack stereoselective methods ‐septanosides, remarkable palette silyl‐based nucleophiles can be reliably employed in our method. This include broad variety useful synthons, easily available silyl‐allyl, silyl‐enol ether, silyl‐ketene acetal, vinylogous silyl‐alkyne and silylazide reagents. Mechanistic investigations suggest that mechanistic shift towards intramolecular aglycone transposition involving pentacoordinate silicon intermediate is likely responsible steering stereoselectivity.

Language: Английский

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Weak Interaction Activates Esters: Reconciling Catalytic Activity and Turnover Contradiction by Tailored Chalcogen Bonding

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(19), P. 13296 - 13305

Published: May 2, 2024

The activation of esters by strong Lewis acids via the formation covalent adducts is a classic strategy to give reactivity; however, this approach frequently incurs limited turnover due low efficiency in dissociation catalyst from stable catalyst-product complex. While use some weak interaction catalysts that can easily dissociate any bonding complexes reaction system would solve problem, poor catalytic activity ester be provided these noncovalent forces turn sets up formidable challenge. Herein, we describe and transformation interactions, which provides promising platform reconcile problems. Several tailored chalcogen-bonding were developed for esters, enabling achieving several inherently reactive Diels–Alder reactions as well ring-opening polymerization lactones through chalcogen interactions. This supramolecular catalysis particularly highlighted its capability promote uncommon involving using dienes bearing electron-withdrawing groups coupled α,β-unsaturated dienophiles substrate incorporating competitive basic sites, typical showed efficiency, while representative hydrogen halogen inactive.

Language: Английский

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