Regiospecific Glycosidation of Unprotected Sugars via Arylboronic Activation

Oshima, Kenji; Aoyama, Yasuhiro

doi:10.1021/ja982395g

Cited by 126 publications

(69 citation statements)

References 18 publications

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“…Calc. C;66.95,H;5.99,N;5.20. Found C;66.85,H;6.05,N;5.40 7, 148.5, 142.1, 132.7, 129.0, 122.1, 117.3, 114.4, 113.0, 70.2, 55.7, 46.8;IR (neat): 3298, 2983IR (neat): 3298, , 1526IR (neat): 3298, , 1437IR (neat): 3298, , 1238IR (neat): 3298, , 1172ESI-MS: m/z, 283 [M-H+CH 3 …”

Section: Accepted Manuscriptunclassified

“…Calc. C;60.44,H;5.07,N;9.40. Found C;60.73,H;4.98,N;9.57 (d, J = 8.4 Hz, 1H), 6.99 (d, J = 8.4 Hz, 2H), 6.82 (d, J = 8.8 Hz, 2H), 5.26 (s, 2H), 5.00 (s, 2H), 3.67 (s, 3H); 13 C-NMR (100 MHz, DMSO-d 6 ): δ 159.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

“…C;60.44,H;5.07,N;9.40. Found C;60.73,H;4.98,N;9.57 (d, J = 8.4 Hz, 1H), 6.99 (d, J = 8.4 Hz, 2H), 6.82 (d, J = 8.8 Hz, 2H), 5.26 (s, 2H), 5.00 (s, 2H), 3.67 (s, 3H); 13 C-NMR (100 MHz, DMSO-d 6 ): δ 159. 2, 153.7, 140.8, 129.3, 127.0, 123.7, 123.3, 122.7, 114.8, 70.4, 55.7, 46.7;IR (neat): 2928IR (neat): , 1453IR (neat): , 1404IR (neat): , 1179IR (neat): , 1124ESI-MS: m/z, 312 [M-H+CH 3 …”

Section: Accepted Manuscriptmentioning

confidence: 99%

“…Calc. C;57.71,H;5.38,N;7.48. Found C;57.63,H;5.50,N;7.29 8, 157.4, 152.9, 141.2, 131.4, 130.7(2C), 129.6 (2C), 123.…”

Section: ] +mentioning

confidence: 99%

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Synthesis and evaluation of functionalized aminobenzoboroxoles as potential anti -cancer agents

Suman

Patel

Kasibotla

et al. 2015

Journal of Organometallic Chemistry

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Section: Accepted Manuscriptunclassified

Section: Accepted Manuscriptmentioning

confidence: 99%

Section: Accepted Manuscriptmentioning

confidence: 99%

“…Calc. C;57.71,H;5.38,N;7.48. Found C;57.63,H;5.50,N;7.29 8, 157.4, 152.9, 141.2, 131.4, 130.7(2C), 129.6 (2C), 123.…”

Section: ] +mentioning

confidence: 99%

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Synthesis and evaluation of functionalized aminobenzoboroxoles as potential anti -cancer agents

Suman

Patel

Kasibotla

et al. 2015

Journal of Organometallic Chemistry

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“…There have been no reports about the effect of borate on increases in regioselectivity in an enzymatic reaction, although arylboronate was used for regiospecific chemical modification of sugar (14,15). In addition, to our knowledge there are not inorganic additives that enhance enantio-, stereo-, or regioselectivity, except for some cations; thus, CaCl 2 (5), NaCl (27), LiCl (12,13), and MgCl 2 (13) enhance the E value of lipase, FeCl 2 and FeCl 3 enhance the E value of alkylsulfatase (16), and MgCl 2 enhances the enantiomeric excess of asymmetric reduction by baker's yeast (10).…”

Section: Improvement Of Reaction Conditions For Pn-5-␣-glc Synthesis mentioning

confidence: 99%

Useof Borate To Control the 5′-Position-Selective MicrobialGlucosylation ofPyridoxine

Wada

Asano

2003

Appl Environ Microbiol

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Nearly 100% 5-position selectivity of transglucosylation from maltodextrin to pyridoxine (PN) by cells of Verticillium dahliae TPU 4900 was observed when the reaction was carried out with borate. The same effect of borate was observed not only during synthesis of pyridoxine 5-␣-D-glucoside by partially purified enzyme of this strain but also during synthesis of this compound by other microorganisms and with other enzymes (␣-glucosidase and cyclomaltodextrin glucanotransferase). The effect was thought to be caused by the formation of a borate complex with 3-and 4-position hydroxyl groups of PN. A decrease in the formation of pyridoxine 5-␣-D-glucoside was observed in the reaction with borate, but this decrease was overcome by optimizing the pH and increasing the amount of cells in the reaction mixture.Pyridoxine 5Ј-␣-D-glucoside (PN-5Ј-␣-Glc) has nutritional importance as vitamin B 6 and exhibits stability in the presence of light irradiation (6,7,25). Recently, we found that some fungi (e.g., Verticillium and Coriolus) enzymatically synthesize PN-5Ј-␣-Glc selectively from pyridoxine (PN) and maltodextrin ( Fig. 1) (2). We selected Verticillium dahliae TPU 4900 (Toyama Prefectural University, Kosugi, Toyama, Japan), which produced PN-5Ј-␣-Glc with a 35% molar yield from 5 mM PN and had 5Ј-position selectivity, by cultivation. The ratio of PN-5Ј-␣-Glc to pyridoxine 4Ј-␣-D-glucoside (PN-4Ј-␣-Glc), one of the position isomers of pyridoxine ␣-D-glucoside (PN-␣-Glc), in the culture broth was 96:4. Moreover, the productivity of V. dahliae TPU 4900 was markedly increased by optimization of the culture and reaction conditions (28). Intact cells of V. dahliae TPU 4900 produced PN-5Ј-␣-Glc with a 41% molar yield from 600 mM PN with a ratio of PN-5Ј-␣-Glc to PN-4Ј-␣-Glc of 85:15 in the preparative reaction. The decrease in the ratio of PN-5Ј-␣-Glc to PN-4Ј-␣-Glc in the reaction with intact cells was caused by the decrease in the rate of PN-5Ј-␣-Glc synthesis in the later stage of the reaction, whereas the rate of PN-4Ј-␣-Glc synthesis was depressed little. During purification of PN-5Ј-␣-Glc from a mixture of PN-␣-Glc by preparative high-performance liquid chromatography or ion-exchange chromatography, some PN-5Ј-␣-Glc was lost when all of the PN-4Ј-␣-Glc was removed, because the physical characteristics of these compounds are similar. Thus, we preferred to minimize the amount of PN-4Ј-␣-Glc during practical production of PN-5Ј-␣-Glc from a high concentration of PN. In this paper, we describe the effect of borate on enhancing 5Ј-position selectivity of enzymatic transglucosylation to PN and the possibility that this effect could be applied to practical formation of PN-5Ј-␣-Glc. This is the first report showing that an inorganic anion enhances the selectivity of the enzyme. Analysis of PN-␣-Glc. Analysis of PN, PN-5Ј-␣-Glc, and PN-4Ј-␣-Glc was done by high-performance liquid chromatography with a Cosmosil 5C18MS-II column (4.6 by 150 mm; Nakalai Tesque, Kyoto, Japan) monitored at 325 nm. The mobile phase was 1% (vol/vol) meth...

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Catalyst‐Controlled Glycosylation

Levi

Jacobsen

2019

Organic Reactions

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Whereas highly practical chemical methods for the synthesis of polypeptides and polynucleotides are well established and in common use, glycan synthesis remains a challenging endeavor largely reserved for specialists in sugar chemistry. Glycosylation reactions are fundamentally challenging relative to peptide and nucleotide couplings, which involve non‐stereogenic linkages that are not strongly affected by the identity of the specific reacting partners. Carbohydrate couplings engage highly variable, stereochemically complex, and densely functionalized reacting partners, while generating a new stereocenter in the glycosidic linkage. Glycosylation methods that can be applied easily and broadly would be greatly enabling to research concerning the role of sugars in biological chemistry and medicine. Recent developments in transition‐metal catalysis and organocatalysis have enabled selective glycosylation reactions with catalyst‐controlled stereo‐ and site selectivity, making headway toward the longstanding goal of achieving generality in chemical glycosylation. This chapter highlights seminal examples of catalyst control in glycosylation, focusing on cases wherein catalyst structure and electronics play a demonstrated role in the stereochemical outcome of a glycosylation reaction.

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Regiospecific Glycosidation of Unprotected Sugars via Arylboronic Activation

Cited by 126 publications

References 18 publications

Synthesis and evaluation of functionalized aminobenzoboroxoles as potential anti -cancer agents

Synthesis and evaluation of functionalized aminobenzoboroxoles as potential anti -cancer agents

Useof Borate To Control the 5′-Position-Selective MicrobialGlucosylation ofPyridoxine

Catalyst‐Controlled Glycosylation

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