Catalytic Approaches to Chemo- and Site-Selective Transformation of Carbohydrates

Chemical Reviews, Год журнала: 2023, Номер 123(10), С. 6793 - 6838

Опубликована: Апрель 26, 2023

Carbohydrates are a fundamental unit playing pivotal roles in all the biological processes. It is thus essential to develop methods for synthesizing, functionalizing, and manipulating carbohydrates further understanding of their functions creation sugar-based functional materials. is, however, not trivial such methods, since densely decorated with polar similarly reactive hydroxy groups stereodefined manner. New approaches chemo- site-selective transformations are, therefore, great significance revolutionizing sugar chemistry enable easier access sugars interest. This review begins brief overview innate reactivity carbohydrates. followed by discussions about catalytic enhance, override, or be orthogonal transformation avoids making list reactions, but rather focuses on summarizing concept behind each reported transformation. The literature references were sorted into sections based underlying ideas approaches, which we hope will help readers have better sense current state innovative field.

Язык: Английский

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Carbene-catalyzed chirality-controlled site-selective acylation of saccharides

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Янв. 2, 2025

Acylation stands as a fundamental process in both biological pathways and synthetic chemical reactions, with acylated saccharides their derivatives holding diverse applications ranging from bioactive agents to building blocks. A longstanding objective organic synthesis has been the site-selective acylation of without extensive pre-protection alcohol units. In this study, we demonstrate that by simply altering chirality N-heterocyclic carbene (NHC) catalysts, site-selectivity saccharide reactions can be effectively modulated. Our investigation reveals intriguing selectivity shift stems combination factors, including match/mismatch inter- / intramolecular hydrogen bonding between NHC catalyst substrates. These findings provide valuable insights into design reaction engineering, highlighting potential glycoside analysis, such fluorescent labelling, α/β identification, orthogonal selective late-stage modifications. The units synthesis. Here, authors

Язык: Английский

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Regioselective Substitution of BINOL

Chemical Reviews, Год журнала: 2024, Номер 124(10), С. 6643 - 6689

Опубликована: Май 9, 2024

1,1′-Bi-2-naphthol (BINOL) has been extensively used as the chirality source in fields of molecular recognition, asymmetric synthesis, and materials science. The direct electrophilic substitution at aromatic rings optically active BINOL developed one most convenient strategies to structurally modify for diverse applications. High regioselectivity achieved reaction with electrophiles. Depending upon conditions patterns, various functional groups can be introduced specific positions, such 6-, 5-, 4-, 3-positions, BINOL. Ortho-lithiation 3-position directed by 2-position have prepare 3- 3,3′-substituted BINOLs. use transition metal-catalyzed C–H activation also explored functionalize 3-, 7-positions. These regioselective substitutions allowed construction tremendous amount derivatives fascinating structures properties reviewed this article. Examples applications BINOLs varying catalysis, chiral sensing are provided.

Язык: Английский

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Controlling Stereoselectivity with Noncovalent Interactions in Chiral Phosphoric Acid Organocatalysis

Chemical Reviews, Год журнала: 2025, Номер unknown

Опубликована: Март 18, 2025

Chiral phosphoric acids (CPAs) have emerged as highly effective Brønsted acid catalysts in an expanding range of asymmetric transformations, often through novel multifunctional substrate activation modes. Versatile and broadly appealing, these benefit from modular tunable structures, compatibility with additives. Given the unique types noncovalent interactions (NCIs) that can be established between CPAs various reactants─such hydrogen bonding, aromatic interactions, van der Waals forces─it is unsurprising catalyst systems become a promising approach for accessing diverse chiral product outcomes. This review aims to provide in-depth exploration mechanisms by which impart stereoselectivity, positioning NCIs central feature connects broad spectrum catalytic reactions. Spanning literature 2004 2024, it covers nucleophilic additions, radical atroposelective bond formations, highlighting applicability CPA organocatalysis. Special emphasis placed on structural mechanistic features govern CPA-substrate well tools techniques developed enhance our understanding their behavior. In addition emphasizing details stereocontrolling elements individual reactions, we carefully structured this natural progression specifics broader, class-level perspective. Overall, findings underscore critical role catalysis significant contributions advancing synthesis.

Язык: Английский

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Electrochemical Synthesis of Glycosyl Fluorides Using Sulfur(VI) Hexafluoride as the Fluorinating Agent

Organic Letters, Год журнала: 2022, Номер 24(12), С. 2294 - 2298

Опубликована: Март 17, 2022

This manuscript describes the electrochemical synthesis of 17 different glycosyl fluorides in 73-98% yields on up to a 5 g scale that relies use SF6 as an inexpensive and safe fluorinating agent. Cyclic voltammetry related mechanistic studies carried out subsequently suggest active species generated through cathodic reduction are transient under these reductive conditions sulfur fluoride byproducts effectively scavenged by Zn(II) generate benign salts.

Язык: Английский

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A synergistic Rh(I)/organoboron-catalysed site-selective carbohydrate functionalization that involves multiple stereocontrol

Nature Chemistry, Год журнала: 2022, Номер 15(3), С. 424 - 435

Опубликована: Дек. 30, 2022

Abstract Site-selective functionalization is a core synthetic strategy that has broad implications in organic synthesis. Particularly, exploiting chiral catalysis to control site selectivity complex carbohydrate functionalizations emerged as leading method unravel unprecedented routes into biologically relevant glycosides. However, robust catalytic systems available overcome multiple facets of stereoselectivity challenges this end still remain scarce. Here we report synergistic Rh(I)- and organoboron-catalysed protocol, which enables access synthetically challenging but arylnaphthalene Our depicts the employment Rh(I) site-selective showcases utility boronic acid compatible co-catalyst. Crucial success our judicious choice suitable organoboron catalyst. We also determine exquisite aspects stereocontrol, including enantio-, diastereo-, regio- anomeric dynamic kinetic resolution, are concomitantly operative.

Язык: Английский

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Asymmetric Transfer Hydrogenation of Heterocyclic Compounds in Continuous Flow Using an Immobilized Chiral Phosphoric Acid as the Catalyst

Synthesis, Год журнала: 2023, Номер 55(15), С. 2361 - 2369

Опубликована: Май 3, 2023

Abstract This manuscript describes transfer hydrogenation of bicyclic nitrogen-containing heterocyclic compounds using the immobilized chiral phosphoric acid catalyst (R)-PS-AdTRIP in batch and continuous flow. A significant improvement enantioselectivities is achieved flow with a fluidized bed reactor packed when rate increased from 0.2 mL/min to 2.0–2.5 mL/min. The optimized conditions consistently provide 4–6% ee higher selectivity than 2 mol% (R)-PS-AdTRIP, are used generate multiple products same reactor.

Язык: Английский

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Asymmetric Pd/Organoboron‐Catalyzed Site‐Selective Carbohydrate Functionalization with Alkoxyallenes Involving Noncovalent Stereocontrol

Angewandte Chemie, Год журнала: 2024, Номер 136(21)

Опубликована: Март 26, 2024

Abstract Herein, we demonstrate the robustness of a synergistic chiral Pd/organoboron system in tackling challenging suite site‐, regio‐, enantio‐ and diastereoselectivity issues across considerable palette biologically relevant carbohydrate polyols, when prochiral alkoxyallenes were employed as electrophiles. In view burgeoning role noncovalent interactions (NCIs) stereoselective synthesis, our mechanistic experiments DFT modeling reaction path unexpectedly revealed that NCIs such hydrogen bonding CH‐π between resting states Pd‐π‐allyl complex borinate saccharide are critically involved stereoselectivity control. Our strategy thus illuminates untapped potential harnessing context transition metal catalysis to tackle challenges functionalization.

Язык: Английский

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Asymmetric Pd/Organoboron‐Catalyzed Site‐Selective Carbohydrate Functionalization with Alkoxyallenes Involving Noncovalent Stereocontrol

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(21)

Опубликована: Март 26, 2024

Abstract Herein, we demonstrate the robustness of a synergistic chiral Pd/organoboron system in tackling challenging suite site‐, regio‐, enantio‐ and diastereoselectivity issues across considerable palette biologically relevant carbohydrate polyols, when prochiral alkoxyallenes were employed as electrophiles. In view burgeoning role noncovalent interactions (NCIs) stereoselective synthesis, our mechanistic experiments DFT modeling reaction path unexpectedly revealed that NCIs such hydrogen bonding CH‐π between resting states Pd‐π‐allyl complex borinate saccharide are critically involved stereoselectivity control. Our strategy thus illuminates untapped potential harnessing context transition metal catalysis to tackle challenges functionalization.

Язык: Английский

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Total Synthesis and Stereochemical Assignment of Enteropeptin A

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(26), С. 17629 - 17635

Опубликована: Июнь 23, 2024

The total synthesis and structural elucidation of the antimicrobial sactipeptide enteropeptin A is reported. Enteropeptin contains a thioaminoketal group with an unassigned stereochemical configuration that embedded in highly unusual thiomorpholine ring. In this synthesis, linear peptide containing dehydroamino acid pendant cysteine residue subjected to Markovnikov hydrothiolation by dithiophosphoric catalyst. This cyclization reaction forms central ring found enteropeptins. Both diastereomers at stereocenter were prepared, their comparison authentic standard allowed for unambiguous assignment natural product be D configuration. inaugural represents first reported date. Moreover, strategy disclosed herein serves as general platform stereochemically defined thiomorpholine-containing peptides, which may enable discovery new cyclic antibiotics.

Язык: Английский

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