116002-34-7Relevant academic research and scientific papers
Monoalkylation of tributyltin activated methyl 4,6-O-benzylidene-α-D-gluco- and -galactopyranosides
Dasgupta,Garegg
, p. 1121 - 1123 (1994)
Monoalkylation of methyl 4,6-O-benzylidene-α-D-gluco- and galactopyranosides could be carried out in good yields using bis(tributyltin) oxide. Regioselectivity, giving predominant 2-substitution, was excellent in the case of D-glucopyranoside. The ratio o
Organotin-catalyzed regioselective benzylation of carbohydrate trans-diols
Xu, Hengfu,Zhang, Ying,Dong, Hai,Lu, Yuchao,Pei, Yuxin,Pei, Zhichao
, p. 4039 - 4042 (2017/10/06)
A convenient approach to regioselective benzylation of carbohydrate trans-diols was developed, where 0.1 equiv. of Bu2SnCl2 and 0.1 equiv. of TBABr were used as the catalysts and 2.0 equiv. of BnCl was used as the benzylation reagent. In most cases, similar or better benzylation regioselectivities and isolated yields were obtained by using catalytic amounts of Bu2SnCl2, rather than stoichiometric amounts of organotin reagents required.
Synthesis and binding affinity analysis of α1-2- and α1-6-O/S-linked dimannosides for the elucidation of sulfur in glycosidic bonds using quartz crystal microbalance sensors
Norberg, Oscar,Wu, Bin,Thota, Niranjan,Ge, Jian-Tao,Fauquet, Germain,Saur, Ann-Kathrin,Aastrup, Teodor,Dong, Hai,Yan, Mingdi,Ramstr?m, Olof
, p. 35 - 42 (2017/10/25)
The role of sulfur in glycosidic bonds has been evaluated using quartz crystal microbalance methodology. Synthetic routes towards α1-2- and α1-6-linked dimannosides with S- or O-glycosidic bonds have been developed, and the recognition properties assessed in competition binding assays with the cognate lectin concanavalin A. Mannose-presenting QCM sensors were produced using photoinitiated, nitrene-mediated immobilization methods, and the subsequent binding study was performed in an automated flow-through instrumentation, and correlated with data from isothermal titration calorimetry. The recorded Kd-values corresponded well with reported binding affinities for the O-linked dimannosides with affinities for the α1-2-linked dimannosides in the lower micromolar range. The S-linked analogs showed slightly disparate effects, where the α1-6-linked analog showed weaker affinity than the O-linked dimannoside, as well as positive apparent cooperativity, whereas the α1-2-analog displayed very similar binding compared to the O-linked structure.
Co2(CO)6-propargyl cation mediates glycosylation reaction by using thioglycoside
Xia, Meng-jie,Yao, Wang,Meng, Xiang-bao,Lou, Qing-hua,Li, Zhong-jun
, p. 2389 - 2392 (2017/05/29)
We discovered that the cobalt-propargyl cation can mediate the glycosylation reaction by activating the thioglycoside donor. The glyco-oxacarbenium cation was formed by transferring the thio-aglycone to the cobalt-propargyl cation that was generated from the cobalt-propargylated acceptor in situ via the activating with Lewis acid. The reactivity of the donor (Armed or dis-armed) and the amount of the Lewis acid control the releasing rate of the cobalt-propargyl group.
Regioselective alkylation of carbohydrates and diols: A cheaper iron catalyst, new applications and mechanism
Ren, Bo,Yan, Ningning,Gan, Lu
, p. 46257 - 46262 (2017/10/11)
As an extension of our previous research on the regioselective protection of carbohydrates and diols, we developed an iron catalyst, Fe(dibm)3 (dibm = diisobutyrylmethane), which has an unusually broad catalytic scope in the selective monoalkyl
An Iron(III) Catalyst with Unusually Broad Substrate Scope in Regioselective Alkylation of Diols and Polyols
Ren, Bo,Ramstr?m, Olof,Zhang, Qiang,Ge, Jiantao,Dong, Hai
, p. 2481 - 2486 (2016/02/12)
In this study, [Fe(dibm)3] (dibm=diisobutyrylmethane) is shown to have unusually broad scope as a catalyst for the selective monoalkylation of a diverse set of 1,2- and 1,3-diol-containing structures. The mechanism is proposed to proceed via a cyclic dioxolane-type intermediate, formed between the iron(III) species and two adjacent hydroxyl groups. This approach represents the first transition-metal catalysts that are able to replace stoichiometric amounts of organotin reagents in regioselective alkylation. The reactions generally lead to very high regioselectivities and high yields, on par with, or better than, previous methods used for regioselective alkylation.
Aqueous Glycosylation of Unprotected Sucrose Employing Glycosyl Fluorides in the Presence of Calcium Ion and Trimethylamine
Pelletier, Guillaume,Zwicker, Aaron,Allen, C. Liana,Schepartz, Alanna,Miller, Scott J.
supporting information, p. 3175 - 3182 (2016/03/19)
We report a synthetic glycosylation reaction between sucrosyl acceptors and glycosyl fluoride donors to yield the derived trisaccharides. This reaction proceeds at room temperature in an aqueous solvent mixture. Calcium salts and a tertiary amine base promote the reaction with high site-selectivity for either the 3′-position or 1′-position of the fructofuranoside unit. Because nonenzymatic aqueous oligosaccharide syntheses are underdeveloped, mechanistic studies were carried out in order to identify the origin of the selectivity, which we hypothesized was related to the structure of the hydroxyl group array in sucrose. The solution conformation of various monodeoxysucrose analogs revealed the co-operative nature of the hydroxyl groups in mediating both this aqueous glycosyl bond-forming reaction and the site-selectivity at the same time.
Acceptor Reactivity in the Total Synthesis of Alginate Fragments Containing α- L -Guluronic Acid and β- D -Mannuronic Acid
Zhang, Qingju,Van Rijssel, Erwin R.,Walvoort, Marthe T. C.,Overkleeft, Herman S.,Van Der Marel, Gijsbert A.,Codée, Jeroen D. C.
supporting information, p. 7670 - 7673 (2015/06/25)
The total synthesis of mixed-sequence alginate oligosaccharides, featuring both β-D-mannuronic acid (M) and α-L-guluronic acid (G), is reported for the first time. A set of GM, GMG, GMGM, GMGMG, GMGMGM, GMGMGMG, and GMGGMG alginates was assembled using GM
Exploring glycosylation reactions under continuous-flow conditions
Cancogni, Damiano,Lay, Luigi
, p. 2873 - 2878 (2015/01/16)
The industrial development of carbohydrate-based drugs is greatly thwarted by the typical challenges inherent in oligosaccharide synthesis. The practical advantages of continuous-flow synthesis in microreactors (high reproducibility, easy scalability, and fast reaction optimization) may offer an effective support to make carbohydrates more attractive targets for drug-discovery processes. Here we report a systematic exploration of the glycosylation reaction carried out under microfluidic conditions. Trichloroacetimidates and thioglycosides have been investigated as glycosyl donors, using both primary and secondary acceptors. Each microfluidic glycosylation has been compared with the corresponding batch reaction, in order to highlight advantages and drawbacks of microreactors technology. As a significant example of multistep continuous-flow synthesis, we also describe the preparation of a trisaccharide by means of two consecutive glycosylations performed in interconnected microreactors.
Modified bleomycin disaccharides exhibiting improved tumor cell targeting
Madathil, Manikandadas M.,Bhattacharya, Chandrabali,Yu, Zhiqiang,Paul, Rakesh,Rishel, Michael J.,Hecht, Sidney M.
, p. 6800 - 6810 (2015/02/19)
The bleomycins (BLMs) are a family of antitumor antibiotics used clinically for anticancer chemotherapy. Their antitumor selectivity derives at least in part from their ability to target tumor cells, a property that resides in the carbohydrate moiety of the antitumor agent. In earlier studies, we have demonstrated that the tumor cell selectivity resides in the mannose carbamoyl moiety of the BLM saccharide and that both the BLM disaccharide and monosaccharide containing the carbamoyl moiety were capable of the delivery/uptake of a conjugated cyanine dye into cultured cancer cell lines. Presently, the nature of the participation of the carbamoyl moiety has been explored further to provide compounds of utility for defining the nature of the mechanism of tumor cell recognition and uptake by BLM saccharides and in the hope that more efficient compounds could be identified. A library of seven disaccharide-Cy5 dye conjugates was prepared that are structural analogues of the BLM disaccharide. These differed from the natural BLM disaccharide in the position, orientation, and substitution of the carbamoyl group. Studies of these compounds in four matched sets of tumor and normal cell lines revealed a few that were both tumor cell selective and internalized 2-4-fold more efficiently than the natural BLM disaccharide.
