66781-85-9

Upstream product

• 93-58-3 benzoic acid methyl ester 
• 17791-36-5 methyl 2,3-di-O-benzyl-α-D-glucopyranoside 
• 93-97-0 benzoic acid anhydride 
• 98-88-4 benzoyl chloride 
• 7177-79-9 methyl 2,3-O-dibenzyl-4,6-O-benzylidene-α-D-glucopyranoside 
• 10364-94-0 1-benzoylimidazole 

Downstream Products

• 140186-47-6 methyl 4-O-(3,4-di-O-acetyl-2,6-dideoxy-α-L-arabino-hexopyranosyl)-6-O-benzoyl-2,3-di-O-benzyl-α-D-glucopyranoside 
• 34819-86-8 3,4-di-O-acetyl-6-deoxy-L-glucal 
• 140186-44-3 methyl 4-O-(3,4,6-tri-O-acetyl-2-deoxy-α-D-arabino-hexopyranosyl)-6-O-benzoyl-2,3-di-O-benzyl-α-D-glucopyranoside 
• 140186-45-4 methyl 4-O-(3,4,6-tri-O-acetyl-2-deoxy-α-D-lyxo-hexopyranosyl)-6-O-benzoyl-2,3-di-O-benzyl-α-D-glucopyranoside 
• 87871-07-6 Methyl 6-O-Benzoyl-2,3-di-O-benzyl-4-deoxy-α-D-xylo-hexopyranoside 

Relevant academic research and scientific papers

Stereoselective Phenylselenoglycosylation of Glycals Bearing a Fused Carbonate Moiety toward the Synthesis of 2-Deoxy-β-galactosides and β-Mannosides

A phenylselenoglycosylation reaction of glycal derivatives mediated by diphenyl diselenide and phenyliodine(III) bis(trifluoroacetate) under mild conditions is described. Stereoselective glycosylation has been achieved by installing fused carbonate on those glycals. 3,4-O-Carbonate galactals and 2,3-O-carbonate 2-hydroxyglucals are converted into corresponding glycosides in good yields with excellent β-selectivity, resulting in 2-phenylseleno-2-deoxy-β-galactosides and 2-phenylseleno-β-mannosides which are good precursors of 2-deoxy-β-galactosides and β-mannosides, respectively.

Regioselective Sulfonylation/Acylation of Carbohydrates Catalyzed by FeCl3 Combined with Benzoyltrifluoroacetone and Its Mechanism Study

A catalytic amount of FeCl3 combined with benzoyl trifluoroacetone (Hbtfa) (FeCl3/Hbtfa = 1/2) was used to catalyze sulfonylation/acylation of diols and polyols using diisopropylethylamine (DIPEA) or potassium carbonate (K2CO3) as a base. The catalytic system exhibited high catalytic activity, leading to excellent isolated yields of sulfonylation/acylation products with high regioselectivities. Mechanism studies indicated that FeCl3 initially formed [Fe(btfa)3] (btfa = benzoyl trifluoroacetonate) with twice the amount of Hbtfa under basic conditions in the solvent acetonitrile at room temperature. Then, Fe(btfa)3 and two hydroxyl groups of the substrates formed a five- or six-membered ring intermediate in the presence of the base. The subsequent reaction between the cyclic intermediate and a sulfonylation reagent led to the selective sulfonylation of the substrate. All key intermediates were captured in the high-resolution mass spectrometry assay, therefore demonstrating this mechanism for the first time.

Stannous chloride as a low toxicity and extremely cheap catalyst for regio-/site-selective acylation with unusually broad substrate scope

This work reports stannous chloride (SnCl2)-catalyzed regio-/site-selective acylation with unusually broad substrate scope. In addition to 1,2- and 1,3-diols and glycosides containing cis-vicinal diol, the substrate scope also includes glycosides without cis-vicinal diol. For such a substrate scope, usually, only methods using stoichiometric amounts of organotin reagents can lead to the same protection pattern with high selectivities and highly isolated yields (84-97% in most cases). Therefore, SnCl2, as a low toxicity and extremely cheap reagent, should be the best catalyst for regio-/site-selective acylation compared with any previously reported reagents. This journal is

DBN-Catalyzed Regioselective Acylation of Carbohydrates and Diols in Ethyl Acetate

The 1,5-diazabicyclo[4.3.0]non-5-ene (DBN)-catalyzed regioselective acylation of carbohydrates and diols in ethyl acetate has been developed. The hydroxyl groups can be selectively acylated by the corresponding anhydride in EtOAc in the presence of a catalytic amount (as low as 0.1 equiv.) of DBN at room temperature to 40 °C. This method avoids metal catalysts and toxic solvents, which makes it comparatively green and mild, and it uses less organic base compared with other selective acylation methods. Mechanism studies indicated that DBN could catalyze the selective acylation of hydroxyl moieties through a dual H-bonding interaction.

Mapping the Relationship between Glycosyl Acceptor Reactivity and Glycosylation Stereoselectivity

The reactivity of both coupling partners—the glycosyl donor and acceptor—is decisive for the outcome of a glycosylation reaction, in terms of both yield and stereoselectivity. Where the reactivity of glycosyl donors is well understood and can be controlled through manipulation of the functional/protecting-group pattern, the reactivity of glycosyl acceptor alcohols is poorly understood. We here present an operationally simple system to gauge glycosyl acceptor reactivity, which employs two conformationally locked donors with stereoselectivity that critically depends on the reactivity of the nucleophile. A wide array of acceptors was screened and their structure–reactivity/stereoselectivity relationships established. By systematically varying the protecting groups, the reactivity of glycosyl acceptors can be adjusted to attain stereoselective cis-glucosylations.

Diisopropylethylamine-triggered, highly efficient, self-catalyzed regioselective acylation of carbohydrates and diols

A diisopropylethylamine (DIPEA)-triggered, self-catalyzed, regioselective acylation of carbohydrates and diols is presented. The hydroxyl groups can be acylated by the corresponding anhydride in MeCN in the presence of a catalytic amount of DIPEA. This method is comparatively green and mild as it uses less organic base compared with other selective acylation methods. Mechanistic studies indicate that DIPEA reacts with the anhydride to form a carboxylate ion, and then the carboxylate ion could catalyze the selective acylation through a dual H-bonding interaction.

Regioselective benzoylation of diols and carbohydrates by catalytic amounts of organobase

A novel metal-free organobase-catalyzed regioselective benzoylation of diols and carbohydrates has been developed. Treatment of diol and carbohydrate substrates with 1.1 equiv. of 1-benzoylimidazole and 0.2 equiv. of 1,8-diazabicyclo[5.4.0]undec-7-ene (DB

A green and convenient method for regioselective mono and multiple benzoylation of diols and polyols

An efficient method for regioselective benzoylation of diols and polyols was developed. The benzoylation is catalyzed by only 0.2 equiv of benzoate anion in acetonitrile with the addition of a stoichiometric amount of benzoic anhydride under very mild condition, leading to high yields. Compared with all other methods, this method shows particular advantage in regioselective multiple benzoylation of polyols, and in avoiding the use of any metal-based catalysts and any amine bases, which is more environment-friendly.

Enhanced basicity of Ag2O by coordination to soft anions

In Ag2O-mediated benzylation, the addition of a catalytic amount of KI can greatly improve reactivity. This is usually attributed to the formation of a more reactive iodo-substituted electrophile. However, our studies show this to be due to the enhanced basicity of Ag2O through coordination of soft iodide anions to the silver atom, and show KI to be an initiator. A catalytic amount of Ag2O and NaBr can catalyze transesterification reactions, indicating the enhanced basicity of Ag2O by bromide. We believe that this is a general effect for metal oxides and soft anions, applicable to a wider range of organic reaction systems. All your base belongs to us: In Ag2O-mediated benzylation, the addition of a catalytic amount of KI can greatly improve reactivity. Our studies show this to be attributable to the enhanced basicity of Ag2O through coordination of soft iodide anions to the silver atom, and show KI to be an initiator. Thus, NaBr as an initiator combined with Ag2O has been successfully used to catalyze transesterification reactions.

Investigation of benzoyloximes as benzoylating reagents: Benzoyl-Oxyma as a selective benzoylating reagent

Hydroxybenzotriazole (HOBt) and HOBt-derived reagents have been classified as Class I explosives, with restrictions on their transportation and storage. We explored a range of benzoylated oxime-based reagents as alternatives to benzoyloxybenzotriazole (BBTZ) for the selective benzoylation of carbohydrate polyols. Benzoylated oximes derived from 2-hydroximino-malononitrile, ethyl 2-hydroximino-2-cyanoacetate (Oxyma), and tert-butyl 2-hydroximino-2-cyanoacetate were most effective for benzoylation of a simple primary alcohol, with yields approaching that obtained for BBTZ. When applied to carbohydrate diols, the most effective reagent was identified as benzoyl-Oxyma. Benzoyl-Oxyma is a highly crystalline, readily prepared alternative to BBTZ, useful in the selective benzoylation of carbohydrate polyols.