4132-31-4Relevant academic research and scientific papers
GaCl3-catalyzed activation of alkynyl glycosides for the synthesis of O-glycosides
Yadav, Jhillu S.,Yadav, Nagendra N.,Gupta, Manoj K.,Srivastava, Nikhil,Subba Reddy, Basi V.
, p. 517 - 520 (2014)
A catalytic amount of GaCl3 (5 mol%) was found to activate alkynyl glycosides effectively under mild reaction conditions to furnish a variety of O-glycosides in good yields with high β-selectivity. Graphical abstract: [Figure not available: see fulltext.]
New class of alkynyl glycoside analogues as tyrosinase inhibitors
Saehlim, Natthiya,Athipornchai, Anan,Sirion, Uthaiwan,Saeeng, Rungnapha
supporting information, (2020/06/01)
A new series of alkynyl glycoside analogues were designed and synthesized from cheap and a commercially available sugar by introduction of various alkynyl and alkyl groups at C-1 and C-6 positions of the sugar ring. The inhibitory abilities of alkynyl gly
Direct dehydrative glycosylation catalyzed by diphenylammonium triflate
Hsu, Mei-Yuan,Lam, Sarah,Lin, Mei-Huei,Lin, Su-Ching,Wang, Cheng-Chung,Wu, Chia-Hui
supporting information, (2020/03/13)
Methods for direct dehydrative glycosylations of carbohydrate hemiacetals catalyzed by diphenylammonium triflate under microwave irradiation are described. Both armed and disarmed glycosyl-C1-hemiacetal donors were efficiently glycosylated in moderate to excellent yields without the need for any drying agents and stoichiometric additives. This method has been successfully applied to a solid-phase glycosylation.
Synthesis of photolabile group protected anomeric acetals and its application in carbohydrate synthesis with the assistance of continuous flow photo-reactor
Tiwari, Varsha,Badavath, Vishnu Nayak,Singh, Adesh Kumar,Kandasamy, Jeyakumar
, p. 227 - 236 (2020/03/18)
Selective deprotection of photolabile anomeric 2-nitrobenzyl acetals was achieved using continuous flow photo-reactor (UV radiation at 355 nm) in methanol-water. Various protecting groups such as acetyl, benzyl, benzoyl, benzylidine, TBS, etc. were found to be highly stable during the photolysis.
An Unexpected FeCl 3/C-Catalyzed β-Stereoselective Glycosylation in the Presence of the C(2)-Benzyl Group
Guo, Hong,Li, Juan,Si, Wenshuai,Tang, Jie,Tang, Tianjun,Wang, Zhongfu,Yang, Guofang,Zhang, Jianbo
, p. 2984 - 3000 (2019/07/22)
An efficient and completely β-stereoselective glycosylation that did not rely on neighboring group participation is described using 2-20 molpercent FeCl 3 /C as the catalyst and benzylated propargyl glycosides as the donors to reach yields up to 96percent under mild condition. With an octatomic-ring intermediate at the α-face of FeCl 3 /C with alkyne of propargyl glycosides, a panel of aglycones comprising aliphatic, alicyclic, unsaturated alcohols, halogenated alcohols, and phenols with different substitution were examined successfully for the exclusive β-stereoselective glycosylation reaction.
N-benzoylglycine/thiourea cooperative catalyzed stereoselective O-glycosidation: Activation of O-glycosyl trichloroacetimidate donors
Dubey, Atul,Sangwan, Rekha,Mandal, Pintu Kumar
, p. 123 - 129 (2019/04/17)
A new practical utility for β-stereoselective glycosylation via activation of O-glycosyl trichloroacetimidate donors using N-benzoylglycine/thiourea cooperative catalysis has been demonstrated. This method represents the first instance where amino acid derived N-benzoylglycine is used as a catalyst for O–glycosylation under mild reaction conditions at ambient temperature. NMR spectroscopy studies suggest that thiourea cocatalyst exhibit a cooperative behaviour that has a strong effect on the reaction rate, yield, and the β-selectivity.
β-Selective Glycosylation by Using O-Aryl-Protected Glycosyl Donors
Otsuka, Yuji,Yamamoto, Toshihiro,Fukase, Koichi
supporting information, p. 2719 - 2723 (2019/07/15)
New glycosyl donors have been developed that contained several para-substituted O-aryl protecting groups and their stereoselectivity for the glycosylation reaction was evaluated. A highly β-selective glycosylation reaction was achieved by using thioglycosides that were protected by 4-nitrophenyl (NP) groups, which were introduced by using the corresponding diaryliodonium triflate. Analysis of the stereoselectivities of several glycosyl donors indicated that the β-glycosides were obtained through an SN2-type displacement from the corresponding α-glycosyl triflate. The NP group could be removed by reduction of the nitro group and acylation, followed by oxidation with ceric ammonium nitrate (CAN).
Visible Light Enables Aerobic Iodine Catalyzed Glycosylation
Krumb, Matthias,Lucas, Tobias,Opatz, Till
supporting information, p. 4517 - 4521 (2019/08/06)
A versatile protocol for light induced catalytic activation of thioglycosides using iodine as an inexpensive and readily available photocatalyst was developed. Oxygen serves as a green and cost-efficient terminal oxidant and irradiation is performed with a common household LED-bulb. The scope of this glycosylation protocol was investigated in the synthesis of O-glycosides with yields up to 95 %.
Silver-catalyzed stereoselective formation of glycosides using glycosyl ynenoates as donors
Dong, Xu,Chen, Li,Zheng, Zhitong,Ma, Xu,Luo, Zaigang,Zhang, Liming
, p. 8626 - 8629 (2018/08/06)
A silver-catalyzed glycosylation reaction employing readily accessible and stable glycosyl ynenoates is developed. This reaction is mostly high yielding and exhibits varying levels of stereoinversion at the anomeric position. Compared to established and versatile Yu's gold catalysis, this chemistry features the use of substantially cheaper AgNTf2.
Efficient Synthesis of α-Glycosyl Chlorides Using 2-Chloro-1,3-dimethylimidazolinium Chloride: A Convenient Protocol for Quick One-Pot Glycosylation
Tatina, Madhu Babu,Khong, Duc Thinh,Judeh, Zaher M. A.
supporting information, p. 2208 - 2213 (2018/06/04)
A mild and convenient method for the synthesis of α-glycosyl chlorides in high 80–96 % yields within 15–30 min using 2-chloro-1,3-dimethylimidazolinium chloride (DMC) is disclosed. The method has a wide substrate scope and is compatible with labile OH protecting groups, including benzyl, acetyl, benzoyl, isopropylidene, benzylidene, TBDMS (tert-butyldimethylsilyl), and TBDPS (tert-butyldiphenylsilyl) groups. The excellent α selectivity obtained in this reaction is attributed to in-situ isomerization of β-glycosyl chlorides to the more stable α-glycosyl chlorides, as demonstrated by 1H NMR spectroscopic studies. Disarmed sugars with OBz or OAc groups at C-2 were chlorinated at a faster rate but ismomerized (β→α) at a slower rate than armed sugars with an OBn group at C-2. More importantly, the method enables highly desirable one-pot glycosylation reactions to take place, thus allowing efficient syntheses of disaccharides and simple O-glycosylated sugars in high overall yields without the need for separation or purification of the α-glycosyl chloride donors. This method will be especially useful for direct glycosylation reactions using glycosyl chloride donors that are unstable upon separation and purification.
