Tetrabutylammonium tribromide (TBATB): a mild and efficient catalyst for O-isopropylidenation of carbohydrates

Khan, Abu T.; Khan, Md. Musawwer; Adhikary, Anubendu

doi:10.1016/j.carres.2010.12.018

Cited by 25 publications

(14 citation statements)

References 30 publications

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“…Following Khan et al, 9 L-rhamnose was treated with tetrabutylammonium tribromide in acetone at room temperature to give acetonide 3 , in 89% yield after work up. Parikh-Doering oxidation 10 of 3 gave the ketone 4a in 58% yield together with 3% of the ketolactone 4b and 16% of starting material 3 .…”

Section: 2 Results and Discussionmentioning

confidence: 99%

“…To a stirred solution of 3 9,13 (5.0 g, 24.4 mmol) in dimethyl sulfoxide (55.0 mL) and dichloromethane (82.5 mL) were added triethylamine (8.5 mL, 61.2 mmol) and sulfur trioxide pyridine complex (7.8 g, 48.9 mmol) at room temperature. After stirring for 1.5 h the reaction mixture was washed with water, and extracted with ethyl acetate.…”

Section: 3 Experimental Sectionmentioning

confidence: 99%

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Alternative synthesis and antibacterial evaluation of 1,5-dideoxy-1,5-imino-l-rhamnitol

Suresh

Wang

Crich

2016

Carbohydrate Research

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A convenient synthesis is described of 5-azido-5-deoxy-2,3-O-isopropylidene-L-rhamnofuranose from L-rhamnose in seven steps and 17% overall yield. A key feature of the synthesis is the selective oxidation of the secondary alcohol in 2,3-O-isopropylidene-L-rhamnofuranose in the presence of the hemiacetal to give the corresponding ketone in good yield using the Parikh-Doering reagent. 5-Azido-5-deoxy-2,3-O-isopropylidene-L-rhamnofuranose is then converted by a literature protocol to 1,5-dideoxy-1,5-imino-L-rhamnitol, which was found to have no significant antimicrobial activity against Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and Escherichia coli.

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Section: 2 Results and Discussionmentioning

confidence: 99%

Section: 3 Experimental Sectionmentioning

confidence: 99%

Alternative synthesis and antibacterial evaluation of 1,5-dideoxy-1,5-imino-l-rhamnitol

Suresh

Wang

Crich

2016

Carbohydrate Research

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“…13 C NMR { 1 H} (100 MHz, MeOH- d 4 ): δ 110.4, 99.4, 80.2, 77.1, 71.8, 70.2, 62.6, 55.2, 28.4, 26.5 ppm. It was synthesized according to the literature …”

Section: Methodsmentioning

confidence: 99%

In Situ Switching of Site-Selectivity with Light in the Acetylation of Sugars with Azopeptide Catalysts

et al. 2019

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We present a novel concept for the in situ control of site-selectivity of catalytic acetylations of partially protected sugars using light as external stimulus and oligopeptide catalysts equipped with an azobenzene moiety. The isomerizable azobenzene-peptide backbone defines the size and shape of the catalytic pocket, while the π-methyl-l-histidine (Pmh) moiety transfers the electrophile. Photoisomerization of the E- to the Z-azobenzene catalyst (monitored via NMR) with an LED (λ = 365 nm) drastically changes the chemical environment around the catalytically active Pmh moiety, so that the light-induced change in the catalyst shape alters site-selectivity. As a proof of principle, we employed (4,6-O-benzylidene)methyl-α-d-pyranosides, which provide a change in regioselectivity from 2:1 (E) to 1:5 (Z) for the monoacetylated products at room temperature. The validity of this new catalyst-design concept is further demonstrated with the regioselective acetylation of the natural product quercetin. In situ irradiation NMR spectroscopy was used to quantify photostationary states under continuous irradiation with UV light.

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“…Khan et al used TBATB as the catalyst for the protection of vicinal diols in sugar moieties. 79 The unprotected hydroxyl groups of the carbohydrate react with TBATB to form dry HBr which in turn catalyses the reaction of the sugar with acetone to form the corresponding O -isopropylidene derivative (Scheme 19). These reactions produce various derivatives in good yields, short time under mild conditions.…”

Section: Synthesis Of Second-generation Brominating Agent and Its App...mentioning

confidence: 99%

Synthetic utility of biomimicking vanadium bromoperoxidase and n-tetrabutylammonium tribromide (TBATB) in organic synthesis

et al. 2022

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Tetrabutylammonium tribromide (TBATB): a mild and efficient catalyst for O-isopropylidenation of carbohydrates

Cited by 25 publications

References 30 publications

Alternative synthesis and antibacterial evaluation of 1,5-dideoxy-1,5-imino-l-rhamnitol

Alternative synthesis and antibacterial evaluation of 1,5-dideoxy-1,5-imino-l-rhamnitol

In Situ Switching of Site-Selectivity with Light in the Acetylation of Sugars with Azopeptide Catalysts

Synthetic utility of biomimicking vanadium bromoperoxidase and n-tetrabutylammonium tribromide (TBATB) in organic synthesis

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