- Thioglucose compound and preparation method thereof
-
The invention provides a thioglucose compound which has the following general formula: Wherein R is selected from H or acetyl. The preparation method of the thioglucose compound is easy to obtain, low in production cost and suitable for industrial product
- -
-
Paragraph 0048-0051
(2021/09/22)
-
- Glycosyl isoxazole compound, preparation method thereof and bactericide
-
The invention relates to the technical field of bactericidal materials, and particularly relates to a glycosyl isoxazole compound, a preparation method thereof and a bactericide. The glycosyl isoxazole compound has a structural general formula shown in the description, wherein R1 is selected from any one of substituted or unsubstituted aromatic groups, and R2 is selected from any one of H, acetyl, benzyl and propargyl. According to the invention, a natural saccharide compound is adopted as the framework, the safety is provided, the toxicity is low, the selectivity is high, residue is not easily generated, the environmental compatibility is good, the active group isoxazole structure is further introduced, and the obtained glycosyl isoxazole compound has advantages of safety, high efficiency, low toxicity, low residue, broad spectrum, resistance generation resistance resistance resistance generation resistance and the like, and further has excellent bactericidal activity.
- -
-
Paragraph 0178-0181; 0185
(2021/04/07)
-
- Cesium Carbonate Catalyzed Esterification of N-Benzyl- N-Boc-amides under Ambient Conditions
-
We report a general activated amide to ester transformation catalyzed by Cs2CO3. Using this approach, esterification proceeds under relatively mild conditions and without the need for a transition metal catalyst. This method exhibits broad substrate scope and represents a practical alternative to existing esterification strategies. The synthetic utility of this protocol is demonstrated via the facile synthesis of crown ether derivatives and the late-stage modification of a representative natural product and several sugars in reasonable yields.
- Ye, Danfeng,Liu, Zhiyuan,Chen, Hao,Sessler, Jonathan L.,Lei, Chuanhu
-
supporting information
p. 6888 - 6892
(2019/09/07)
-
- Zn-Catalyzed tert-Butyl Nicotinate-Directed Amide Cleavage as a Biomimic of Metallo-Exopeptidase Activity
-
A two-step catalytic amide-to-ester transformation of primary amides under mild reaction conditions has been developed. A tert-butyl nicotinate (tBu nic) directing group is easily introduced onto primary amides via Pd-catalyzed amidation with tert-butyl 2-chloronicotinate. A weak base (Cs2CO3 or K2CO3) at 40-50 °C can be used provided that 1,1′-bis(dicyclohexylphosphino)ferrocene is selected as ligand. The tBu nic activated amides subsequently allow Zn(OAc)2-catalyzed nonsolvolytic alcoholysis in tBuOAc at 40-60 °C under neutral reaction conditions. The activation mechanism is biomimetic: the C3-ester substituent of the pyridine in the directing group populates the trans-conformer suitable for Zn-chelation, C=Oamide-Zn-Ndirecting group, and Zn-coordinated alcohol is additionally activated as a nucleophile by hydrogen bonding with the acetate ligand of the catalyst. Additionally, the acetate ligand assists in intramolecular O-to-N proton transfer. The chemoselectivity versus other functional groups and compatibility with challenging reaction partners, such as peptides, sugars, and sterols, illustrates the synthetic applicability of this two-step amide cleavage method. The tBu nic amides do not require purification before cleavage. Preliminary experiments also indicate that other weak nucleophiles can be used such as (hetero)arylamines (transamidation) as exemplified by 8-aminoquinoline.
- Wybon, Clarence C. D.,Mensch, Carl,Hollanders, Charlie,Gadais, Charlène,Herrebout, Wouter A.,Ballet, Steven,Maes, Bert U. W.
-
p. 203 - 218
(2018/01/17)
-
- Visible-Light Photocatalysis Employing Dye-Sensitized Semiconductor: Selective Aerobic Oxidation of Benzyl Ethers
-
The aerobic oxidation is an attractive approach toward environmentally benign synthesis of fine chemicals. In addition, dye-sensitized semiconductors are underdeveloped photocatalysts for selective organic synthesis. With the aid of catalytic eosin Y-sensitized titanium dioxide, we have developed efficient aerobic photooxidation of benzyl ethers to benzoates, featuring low cost, high atom economy, broad substrate scope, and user-friendly setup. Furthermore, preliminary mechanistic studies established that the reaction pathway likely entails a photoinduced, radical-based two-step process via an isolable peroxide intermediate.
- Ren, Li,Yang, Ming-Meng,Tung, Chen-Ho,Wu, Li-Zhu,Cong, Huan
-
p. 8134 - 8138
(2017/12/08)
-
- Tetrofuranose nucleoside phosphonic acids: Synthesis and properties
-
New isoelectronic, non-isosteric phosphonate analogues of nucleoside 5'-phosphates featuring the phosphorus moiety directly attached on the sugar ring in the C4' position are described. The analogues were synthesised by a nucleosidation reaction from tetr
- Polakova, Ivana,Budesinsky, Milos,Tocik, Zdenek,Rosenberg, Ivan
-
experimental part
p. 503 - 536
(2011/12/04)
-
- Regio- and stereoselective anomeric esterification of glucopyranose 1,2-diols and a facile preparation of 2-O-acetylated glucopyranosyl trichloroacetimidates from the corresponding 1,2-diols
-
A highly regio- and stereoselective anomeric esterification of 3-O-allyl (or benzyl, or benzoyl)-4,6-O-isopropylidene-α,β-d-glucopyranose with acetyl chloride, or allyl chloroformate, or ethyl chloroformate gave the corresponding 2-OH, 1-β-acetates or -carbonates in excellent yields. The 2-OH, 1-β-acetates were readily converted to the corresponding 2-O-acetylated glucopyranosyl trichloroacetimidates by reaction with trichloroacetonitrile via base promoted acetyl migration, while the 2-OH, 1-β-carbonates were good glycosyl acceptors for the synthesis of (1→2)-linked oligosaccharides.
- Zhang, Jianjun,Liang, Xiaomei,Wang, Daoquan,Kong, Fanzuo
-
p. 797 - 805
(2008/02/02)
-
- Acylation of carbohydrates over Al2O3: Preparation of partially and fully acylated carbohydrate derivatives and acetylated glycosyl chlorides
-
Selective and per-O-acylation of carbohydrate derivatives using acyl chlorides and Al2O3, a solid support reagent, is reported. This protocol does not require the addition of any base or activator. This methodology has been further extended to the selective acylation of carbohydrate diols and the one-pot preparation of acetylated glycosyl chlorides direct from free reducing sugars. The yields obtained in most of the cases are excellent.
- Tiwari, Pallavi,Misra, Anup Kumar
-
p. 339 - 350
(2007/10/03)
-
- Selective deprotection of terminal isopropylidene acetals and trityl ethers using HClO4 supported on silica gel
-
Terminal isopropylidene acetals are selectively cleaved to the corresponding 1,2-diols in good to excellent yields in 6-24 h at room temperature by using the 'HClO4?SiO2' reagent system. Likewise, trityl ethers are readily cleaved to the corresponding alcohols in good to excellent yields within 2-3 h at room temperature. Work-up involves merely filtration of the reagent followed by purification of the crude product.
- Agarwal, Aditi,Vankar, Yashwant D.
-
p. 1661 - 1667
(2007/10/03)
-
- Rapid carbohydrate protecting group manipulations assisted by microwave dielectric heating
-
The protocols for oligosaccharide synthesis are often tedious due to extended synthetic routes and reaction times. We herein describe methods assisted by microwave dielectric heating, which enable very short reaction times and high yields for the introduction and removal of eleven of the most commonly used protecting groups in carbohydrate syntheses. Several examples are reported, where solid supported reagents in combination with microwave dielectric heating have been used. This results in both faster and easier synthesis and purification.
- Soederberg, Eva,Westman, Jacob,Oscarson, Stefan
-
p. 397 - 410
(2007/10/03)
-
- A novel and efficient method for the oxidative removal of O-benzyl protective groups of carbohydrates by tetrabutylammonium peroxydisulfate
-
Various benzyl ethers of carbohydrates have been selectively oxidized to the corresponding benzoate esters 2a-j with tetrabutylammonium peroxydisulfate under neutral conditions followed by debenzoylation with sodium methoxide to afford the debenzylated carbohydrates 3a-j in good overall yields. Noteworthy is that highly chemoselective reactions were achieved with the co-existence of other functionalities. Thieme Stuttgart.
- Chen, Fen-Er,Peng, Zuo-Zhong,Fu, Han,Meng, Ge,Cheng, Yu,Lü, Yin-Xiang
-
p. 627 - 628
(2007/10/03)
-
- Nucleophilic Substitution Reactions of (Alkoxymethylene)dimethylammonium Chloride
-
The use of imidate esters as potential replacements for diethyl azodicarboxylate and triphenylphosphine in the Mitsunobu reaction is described. A series of secondary alcohols were allowed to react with (chloromethylene)dimethylammonium chloride, generated from dimethylformamide (DMF) and oxalyl chloride, to give imidate esters. Reaction of these salts with potassium benzoate or potassium phthalimide gave the products of SN2 substitution in excellent yields with clean inversion of stereochemistry. Optimization of reaction conditions is discussed as a means to increase the atom economy of the process by minimizing the quantity of nucleophile required.
- Barrett, Anthony G. M.,Braddock, D. Christopher,James, Rachel A.,Koike, Nobuyuki,Procopiou, Panayiotis A.
-
p. 6273 - 6280
(2007/10/03)
-
- Synthesis of benzoyl and dodecanoyl derivatives from protected carbohydrates under focused microwave irradiation
-
A microwave assisted phase transfer transesterification in basic medium with methyl benzoate was studied for several carbohydrates. Small amounts of DMF were necessary to provide good yields (96-76%) within 15 minutes. This method was extended to the synt
- Limousin, Corinne,Cleophax, Jeannine,Loupy, Andre,Petit, Alain
-
p. 13567 - 13578
(2007/10/03)
-
- 2-PHENYL-1,3-BENZODITHIOLYLIUM TRIFLUOROMETHANESULFONATE: A REAGENT FOR THE CONVERSION OF ALCOHOLS INTO BENZYL ETHERS AND BENZOATES UNDER MILD CONDITIONS.
-
2-Phenyl-1,3-benzodithiolylium trifluoromethanesulfonate, easily prepared from 1,2-benzenedithiol, converts alcohols into dithioorthoesters and ultimately, benzyl ethers (Bu3SnH) and benzoates (HgO/HBF4).
- Mocerino, Mauro,Stick, Robert V.
-
p. 3051 - 3054
(2007/10/02)
-
- Mild Deprotection of Benzyl Ether Protective Groups with Ozone
-
Benzyl ether protective groups are oxidatively removed by ozone under relatively mild conditions.Reaction products are benzoic ester, benzoic acid, and the corresponding alcohol.Subsequent deacylation with sodium methoxide affords a convenient debenzylation technique which has been applied to various O-benzyl protected carbohydrates 1 to afford the deprotected species 2.Glycosides and acetals are unaffected by the treatment.
- Angibeaud, Pierre,Defaye, Jacques,Gadelle, Andree,Utille, Jean-Pierre
-
p. 1123 - 1125
(2007/10/02)
-
- A FACILE METHOD FOR THE OXIDATIVE REMOVAL OF BENZYL ETHERS: THE OXIDATION OF BENZYL ETHERS TO BENZOATES BY RUTHENIUM TETRAOXIDE
-
A series of benzyl ethers has been prepared and their oxidation to benzoate esters by ruthenium tetraoxide has been studied.Yields for the oxidation step range from 54 to 96 percent.
- Schuda, Paul Francis,Cichowicz, Melissa B.,Heimann, Martha R.
-
p. 3829 - 3830
(2007/10/02)
-