Boronic Acid-Catalyzed Regioselective Koenigs–Knorr-Type Glycosylation

Shimada, Naoyuki; Sugimoto, Tomoya; Noguchi, M.; Ohira, Chikako; Kuwashima, Yutaro; Sato, Noriko; Makino, Kazuishi

doi:10.1021/acs.joc.1c00130

Cited by 13 publications

(7 citation statements)

References 67 publications

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“…Promising results were only obtained when a panel of boronic acids was evaluated as potential co-catalysts (Table 1). While aryl-based boronic acids were more commonly employed as catalysts in cases involving carbohydrate diol complexations 62,63,66 , we observed that in our instance vinylboronic acid performed comparatively much better as a catalyst, while aliphatic boronic acids 22 and 23 were deleterious in the reaction. Density functional theory (DFT) studies (Supplementary Section 'Computational Details') suggested that fine-tuning electron-donating and conjugation effects on the boronate substituent is pivotal to increase nucleophilicity and also to provide stability to the negatively charged boronate resting-state species.…”

Section: Establishment Of the Synergistic Catalysis Methodologymentioning

confidence: 58%

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

et al. 2022

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

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Section: Establishment Of the Synergistic Catalysis Methodologymentioning

confidence: 58%

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

et al. 2022

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“…31 group that promotes the catalytic active boronate formation by generating an internal B−N dative bond. 32,33 Concurrently, we have reported benzoxaborole (BO) catalysts (Figure 2A). 34 The outstanding cis-1,2-diol affinity of BO 35,36 offers good activity and regioselectivity in the catalyst-controlled modifications of carbohydrates.…”

Section: ■ Introductionmentioning

confidence: 77%

Benzoxaborole Catalyst Embedded with a Lewis Base: A Highly Active and Selective Catalyst for cis-1,2-diol Modification

Kusano,

Yamada,

Hagihara

2024

J. Org. Chem.

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The regioselective modification of polyols allows rapid access to their derivatives, thereby accelerating the polyolrelated biology and drug discovery. We previously reported that benzoxaborole is a potent catalyst for the regioselective modification of polyols containing a cis-1,2-diol structure. In this study, we developed a bifunctional benzoxaborole catalyst embedded with a Lewis base. Benzoxaborole and Lewis base groups were designed to cooperatively activate a substrate (cis-1,2-diol) and reactant (electrophile), respectively, hence lowering the reaction barrier for the cis-1,2-diol moiety. The bifunctional catalyst indeed exhibited a significantly higher catalytic activity and selectivity for cis-1,2-diol modifications rather than a benzoxaborole catalyst without a Lewis base group. Mechanistic analyses, using both experimental and theoretical methods, supported the design of our catalyst. The bifunctional catalyst reported herein would be a new tool for the straightforward synthesis of polyol derivatives.

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“…The same concept was successfully applied to the Koenigs−Knorr-type glycosylation reaction to enable regioselective glycosylation of nonprotected fucopyranoside and other pyranoside sugars with their 6-OH protected (Figure 13b). 70 Stereoselective formation of the 1,2-cis-α-glycosidic linkage is a challenging task due to nonavailability of neighboring-group participation from a 2-O-acyl protecting group in the glycosyl donor. In 2015, Toshima, Takahashi, and co-workers found that a boronate ester preformed from a glycosyl acceptor worked as a catalyst to promote regioselective 1,2-cis-stereoselective glycosylation reaction with a 1,2-anhydro glycosyl donor (Figure 14a).…”

Section: Boronate Estermentioning

confidence: 99%

“…The observed regioselectivity was explained by the cyclic boronate ester formation with cis -1,2-diol followed by the reaction at the sterically less hindered equatorial hydroxy group. The same concept was successfully applied to the Koenigs–Knorr-type glycosylation reaction to enable regioselective glycosylation of nonprotected fucopyranoside and other pyranoside sugars with their 6-OH protected (Figure b) …”

Section: Covalent Bond-forming Catalysis With 12-diolsmentioning

confidence: 99%

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

Yamatsugu

Kanai

2023

Chem. Rev.

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

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Boronic Acid-Catalyzed Regioselective Koenigs–Knorr-Type Glycosylation

Cited by 13 publications

References 67 publications

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

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

Benzoxaborole Catalyst Embedded with a Lewis Base: A Highly Active and Selective Catalyst for cis-1,2-diol Modification

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

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