H2SO4-SiO2: Highly Efficient and Reusable Catalyst for per-O-Acetylation of Carbohydrates Under Solvent-Free Conditions

Zhang, Jianbo; Zhang, Bo; Zhou, Junxia; Li, Juan; Shi, Chunjuan; Huang, Ting; Wang, Zhongfu; Tang, Jie

doi:10.1080/07328303.2011.621042

Cited by 22 publications

(2 citation statements)

References 34 publications

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“…Acetylation and acetolysis. To the methyl heptoside mixture 8 first 100 cm 3 Ac 2 O were added and the mixture was stirred for several minutes before 1 g H 2 SO 4 –SiO 2 [39] was added at rt. The reaction mixture started to warm and within 1 h the reaction mixture turned homogenous.…”

Section: Methodsmentioning

confidence: 99%

Methyl glycosides via Fischer glycosylation: translation from batch microwave to continuous flow processing

Aronow¹,

Stanetty²,

Baxendale

et al. 2018

Monatsh Chem

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A continuous flow procedure for the synthesis of methyl glycosides (Fischer glycosylation) of various monosaccharides using a heterogenous catalyst has been developed. In-depth analysis of the isomeric composition was undertaken and high consistency with corresponding results observed under microwave heating was obtained. Even in cases where addition of water was needed to achieve homogeneity—a prerequisite for the flow experiments—no detrimental effect on the conversion was found. The scalability was demonstrated on a model case (mannose) and as part of the target-oriented synthesis of d-glycero-d-manno heptose, both performed on multigram scale.Graphical abstract Electronic supplementary materialThe online version of this article (10.1007/s00706-018-2306-8) contains supplementary material, which is available to authorized users.

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Section: Methodsmentioning

confidence: 99%

Methyl glycosides via Fischer glycosylation: translation from batch microwave to continuous flow processing

Aronow¹,

Stanetty²,

Baxendale

et al. 2018

Monatsh Chem

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show abstract

“…This latter activates the electrophilic character of the acyl moiety of the Ac 2 O and can be either a protic/Lewis acid (more frequently) or a nucleophilic catalyst. Representative examples [10] of acetylation catalysts are: Dy(OTf) 3 [11], Cu(ClO 4 ) 2 [12], iodine [13], silica sulfuric acid (SSA) [14,15], DABCO (1,4-diazabicyclo[2.2.2]octane) [16], diazepinium perchlorate [17], methanesulfonic acid [18], In(OTf) 3 [19], Sm(OTf) 3 [20], Sc(OTf) 3 [21], sulfamic acid [22], and sulfonic acid functionalized nano γ-Al 2 O 3 [23]. These approaches yield peracetylation products, which in turn, are precursors for the synthesis of useful building-blocks.…”

Section: Acylation Reactionsmentioning

confidence: 99%

Solvent-Free Approaches in Carbohydrate Synthetic Chemistry: Role of Catalysis in Reactivity and Selectivity

et al. 2020

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Owing to their abundance in biomass and availability at a low cost, carbohydrates are very useful precursors for products of interest in a broad range of scientific applications. For example, they can be either converted into basic chemicals or used as chiral precursors for the synthesis of potentially bioactive molecules, even including nonsaccharide targets; in addition, there is also a broad interest toward the potential of synthetic sugar-containing structures in the field of functional materials. Synthetic elaboration of carbohydrates, in both the selective modification of functional groups and the assembly of oligomeric structures, is not trivial and often entails experimentally demanding approaches practiced by specialized groups. Over the last years, a large number of solvent-free synthetic methods have appeared in the literature, often being endowed with several advantages such as greenness, experimental simplicity, and a larger scope than analogous reactions in solution. Most of these methods are catalytically promoted, and the catalyst often plays a key role in the selectivity associated with the process. This review aims to describe the significant recent contributions in the solvent-free synthetic chemistry of carbohydrates, devoting a special critical focus on both the mechanistic role of the catalysts employed and the differences evidenced so far with corresponding methods in solution.

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Site‐Selective Aryl Diazonium Installation onto Protein Surfaces at Neutral pH using a Maleimide‐Functionalized Triazabutadiene

et al. 2023

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Aryl diazonium cations are versatile bioconjugation reagents due to their reactivity towards electron‐rich aryl residues and secondary amines, but historically their usage has been hampered by both their short lifespan in aqueous solution and the harsh conditions required to generate them in situ. Triazabutadienes address many of these issues as they are stable enough to endure multiple‐step chemical syntheses and can persist for several hours in aqueous solution, yet upon UV‐exposure rapidly release aryl diazonium cations under biologically‐relevant conditions. This paper describes the synthesis of a novel maleimide‐functionalized triazabutadiene suitable for site‐selectively installing aryl diazonium cations into proteins at neutral pH; we show reaction with this molecule and a surface‐cysteine of a thiol disulfide oxidoreductase. Through photoactivation of the site‐selectively installed triazabutadiene motifs, we generate aryl diazonium functionality, which we further derivatize via azo‐bond formation to electron‐rich aryl species, showcasing the potential utility of this strategy for the generation of photoswitches or protein‐drug conjugates.

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H₂SO₄-SiO₂: Highly Efficient and Reusable Catalyst for per-O-Acetylation of Carbohydrates Under Solvent-Free Conditions

Cited by 22 publications

References 34 publications

Methyl glycosides via Fischer glycosylation: translation from batch microwave to continuous flow processing

Methyl glycosides via Fischer glycosylation: translation from batch microwave to continuous flow processing

Solvent-Free Approaches in Carbohydrate Synthetic Chemistry: Role of Catalysis in Reactivity and Selectivity

Site‐Selective Aryl Diazonium Installation onto Protein Surfaces at Neutral pH using a Maleimide‐Functionalized Triazabutadiene

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