91685-06-2

Upstream product

• 110-86-1 pyridine 
• 98-88-4 benzoyl chloride 
• 18031-56-6 methyl-[O⁴,O⁶-((R)-benzylidene)-O³-trifluoroacetyl-α-D-glucopyranoside] 
• 67-56-1 methanol 
• 389-04-8 methyl-[O²-benzoyl-O⁴,O⁶-((R)-benzylidene)-O³-trifluoroacetyl-α-D-glucopyranoside] 
• 64-17-5 ethanol 
• 3162-96-7 4,6-O-benzylidene-1-O-methyl-α-D-glucopyranoside 
• 54769-36-7 N-benzoyloxybenzotriazole 
• 93-97-0 benzoic acid anhydride 
• 100-52-7 benzaldehyde 
• 97-30-3 methyl-alpha-D-glucopyranoside 
• 65-85-0 benzoic acid 
• 1202384-88-0 C₂₃H₂₄O₉ 
• 2641-79-4 methyl 2,3,4,6-tetrakis-O-trimethylsilyl-α-D-glucopyranoside 

Downstream Products

• 198837-07-9 methyl-[O³-acetyl-O²-benzoyl-O⁴,O⁶-((R)-benzylidene)-α-D-glucopyranoside] 
• 169218-38-6 methyl 2-O-benzoyl-4,6-O-benzylidene-3-O-methanesulfonyl-α-D-glucopyranoside 
• 66674-14-4 methyl-[O²-benzoyl-O⁴,O⁶-((R)-benzylidene)-O³-(toluene-4-sulfonyl)-α-D-glucopyranoside] 
• 33535-04-5 methyl 3-O-benzoyl-4,6-O-benzylidene-α-D-glucopyranoside 
• 389-04-8 methyl-[O²-benzoyl-O⁴,O⁶-((R)-benzylidene)-O³-trifluoroacetyl-α-D-glucopyranoside] 
• 130052-72-1 methyl O-(tetra-O-acetyl-β-D-glucopyranosyl)-(1->4)-O-(tri-O-acetyl-β-D-glucopyranosyl)-(1->3)-2-O-benzoyl-4,6-O-benzylidene-α-D-glucoside 
• 130052-73-2 methyl O-(tetra-O-acetyl-β-D-glucopyranosyl)-(1->3)-O-(tri-O-acetyl-β-D-glucopyranosyl)-(1->3)-2-O-benzoyl-4,6-O-benzylidene-α-D-glucoside 
• 118246-03-0 methyl 2,3,4-tri-O-acetyl-O-α-L-rhamnopyranosyI-(1->3)-2-O-benzoyl-4,6-O-benzylidene-O-α-D-gluco-pyranoside 
• 118246-04-1 methyl 2-O-benzoyl-4,6-O-benzylidene-3-O-(2,3,4-tri-O-acetyl-α-D-rhamnopyranosyl)-α-D-glucopyranoside 
• 99679-79-5 methyl 4,6-O-(phenylmethylene)-2-benzoate-3-(trifluoromethanesulfonate)-α-D-glucopyranoside 
• 88415-66-1 Bis(methyl-2-O-benzoyl-4,6-O-benzyliden-α-D-glucopyranosid)-3,3'-carbonat 
• 88410-53-1 Methyl-2-O-benzoyl-4,6-O-benzyliden-3-chlor-3-desoxy-α-D-allopyranosid 
• 439-03-2 2,3,4,6-tetra-O-acetyl-α-D-galactopyranosyl fluoride 
• 115828-08-5 C₃₄H₅₂N₂O₈Si₂ 

Relevant academic research and scientific papers

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.

An inexpensive catalyst, Fe(acac)3, for regio/site-selective acylation of diols and carbohydrates containing a 1,2-: Cis -diol

This work describes the [Fe(acac)3] (acac = acetylacetonate)-catalyzed, regio/site-selective acylation of 1,2- and 1,3-diols and glycosides containing a cis-vicinal diol. The iron(iii) catalysts initially formed cyclic dioxolane-type intermediates with substrates between the iron(iii) species and vicinal diols, and the efficient and selective acylation of one hydroxyl group was subsequently achieved by adding acylation reagents in the presence of diisopropylethylamine (DIPEA) under mild conditions. This reaction generally produced high selectivities and highly isolated yields with the same protection pattern as that achieved with dibutyl tinoxide-mediated schemes.

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.

Enhanced site-selectivity in acylation reactions with substrate-optimized catalysts on solid supports

A concept for site selective acylation of poly-hydroxylated substrates is presented where polymer-supported catalysts are employed: catalytically active DMAP units were combined with a library of small molecule peptides attached to the solid phase with the goal to identify substrate-optimized catalysts through library screening. For selected examples, we demonstrate how the optimized catalysts can convert “their” substrate with a markedly enhanced site-selectivity, compared to only DMAP. Due to the solid support, product purification is significantly simplified, and the peptidic catalysts can be easily reused in multiple cycles while conserving its efficiency.

Highly Efficient Selective Benzylation of Carbohydrates Catalyzed by Iron(III) with Silver Oxide and Bromide Anion as Co-catalysts

A highly efficient, green, and regioselective method for the benzylation of diols and polyols was developed. With the use of Ag2O (0.6 equiv.) and tetrabutylammonium bromide (0.1 equiv.) as co-catalysts, the iron(III)-catalyzed benzylation reaction proceeded to completion at 40 °C within 2–3 h and gave the products in high yields with high regioselectivities. A mechanism involving the principle of enhanced basicity of Ag2O by soft anions was proposed.

Highly Regioselective Monoacylation of Unprotected Glucopyranoside Using Transient Directing-Protecting Groups

The regioselective functionalization of monosaccharides is notoriously achieved using metal catalysis, lengthy synthetic strategies requiring protection/deprotection, various enzymes, or other methods that target cis-diols (and thus cannot be used with glucopyranose derivatives), In this paper, we report a new method using selected boronic acids as temporary protecting groups, and describe its application to the regioselective functionalization of methyl α-d-glucopyranoside, the most difficult monosaccharide to functionalize regioselectively. Generally, reactions of glucopyranosides may lead to a plethora of mono- and polyfunctionalized derivatives, yet our method gave the 3-O-acetylated, 2-O-benzoylated, and 2-O-pivaloylated derivatives of methyl α-d-glucopyranoside as major products. We focused on the use of recyclable and green temporary protecting groups (in a one-pot reaction) and on the modulation of the intramolecular hydrogen-bonding network using selected arylboronic acids. A complete scalable procedure leading to a single regioisomer from unprotected methyl α-d-glucopyranoside is presented.

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.

Regioselective acylation of diols and triols: The cyanide effect

Central topics of carbohydrate chemistry embrace structural modifications of carbohydrates and oligosaccharide synthesis. Both require regioselectively protected building blocks that are mainly available via indirect multistep procedures. Hence, direct pr

Wittig Reaction: Domino Olefination and Stereoselectivity DFT Study. Synthesis of the Miharamycins' Bicyclic Sugar Moiety

2-O-Acyl protected-d-ribo-3-uloses reacted with [(ethoxycarbonyl)methylene]triphenylphosphorane in acetonitrile to afford regio- and stereoselectively 2-(Z)-alkenes in 10-60 min under microwave irradiation. This domino reaction is proposed to proceed via tautomerization of 3-ulose to enol, acyl migration, tautomerization to the 3-O-acyl-2-ulose, and Wittig reaction. Alternatively, in chloroform, regioselective 3-olefination of 2-O-pivaloyl-3-uloses gave (E)-alkenes, key precursors for the miharamycins' bicyclic sugar moiety.