1423496-75-6Relevant academic research and scientific papers
Automated Quantification of Hydroxyl Reactivities: Prediction of Glycosylation Reactions
Chang, Chun-Wei,Lin, Mei-Huei,Chan, Chieh-Kai,Su, Kuan-Yu,Wu, Chia-Hui,Lo, Wei-Chih,Lam, Sarah,Cheng, Yu-Ting,Liao, Pin-Hsuan,Wong, Chi-Huey,Wang, Cheng-Chung
supporting information, p. 12413 - 12423 (2021/05/03)
The stereoselectivity and yield in glycosylation reactions are paramount but unpredictable. We have developed a database of acceptor nucleophilic constants (Aka) to quantify the nucleophilicity of hydroxyl groups in glycosylation influenced by the steric, electronic and structural effects, providing a connection between experiments and computer algorithms. The subtle reactivity differences among the hydroxyl groups on various carbohydrate molecules can be defined by Aka, which is easily accessible by a simple and convenient automation system to assure high reproducibility and accuracy. A diverse range of glycosylation donors and acceptors with well-defined reactivity and promoters were organized and processed by the designed software program “GlycoComputer” for prediction of glycosylation reactions without involving sophisticated computational processing. The importance of Aka was further verified by random forest algorithm, and the applicability was tested by the synthesis of a Lewis A skeleton to show that the stereoselectivity and yield can be accurately estimated.
Catalytic and Photochemical Strategies to Stabilized Radicals Based on Anomeric Nucleophiles
Chen, Zhenhao,Hong, Xin,Rui, Jinyan,Walczak, Maciej A.,Zhang, Shuo-Qing,Zhu, Feng
supporting information, p. 11102 - 11113 (2020/07/13)
Carbohydrates, one of the three primary macromolecules of living organisms, play significant roles in various biological processes such as intercellular communication, cell recognition, and immune activity. While the majority of established methods for the installation of carbohydrates through the anomeric carbon rely on nucleophilic displacement, anomeric radicals represent an attractive alternative because of their functional group compatibility and high anomeric selectivities. Herein, we demonstrate that anomeric nucleophiles such as C1 stannanes can be converted into anomeric radicals by merging Cu(I) catalysis with blue light irradiation to achieve highly stereoselective C(sp3)-S cross-coupling reactions. Mechanistic studies and DFT calculations revealed that the C-S bond-forming step occurs via the transfer of the anomeric radical directly to a sulfur electrophile bound to Cu(II) species. This pathway complements a radical chain observed for photochemical metal-free conditions where a disulfide initiator can be activated by a Lewis base additive. Both strategies utilize anomeric nucleophiles as efficient radical donors and achieve a switch from an ionic to a radical pathway. Taken together, the stability of glycosyl nucleophiles, a broad substrate scope, and high anomeric selectivities observed for the thermal and photochemical protocols make this novel C-S cross coupling a practical tool for late-stage glycodiversification of bioactive natural products and drug candidates.
TMSBr-mediated solvent- and work-up-free synthesis of α-2-deoxyglycosides from glycals
Hsu, Mei-Yuan,Liu, Yi-Pei,Lam, Sarah,Lin, Su-Ching,Wang, Cheng-Chung
, p. 1758 - 1764 (2016/10/05)
The thio-additions of glycals were efficiently promoted by a stoichiometric amount of trimethylsilyl bromide (TMSBr) to produce S-2-deoxyglycosides under solvent-free conditions in good to excellent yields. In addition, with triphenylphosphine oxide as an additive, the TMSBr-mediated direct glycosylations of glycals with a large range of alcohols were highly α-selective.
Iterative α-Glycosylation Strategy for 2-Deoxy- and 2,6-Dideoxysugars: Application to the One-Pot Synthesis of Deoxysugar-Containing Oligosaccharides
Chen, Jiun-Han,Ruei, Jyh-Herng,Mong, Kwok-Kong Tony
supporting information, p. 1827 - 1831 (2015/10/05)
This paper describes the development of an iterative and α-selective glycosylation method for 2-deoxyglycosyl and 2,6-dideoxythioglycoside donors based on the DMF modulation concept. We used NMR spectroscopy to probe the 2-deoxyglycosyl imidinium intermediate and elucidated the conditions to decrease the formation of glycal and thus to increase the reaction yields. Further elaboration of the glycosylation method opened the gate for an iterative one-pot synthesis of 2-deoxy- and 2,6-dideoxyglycoside-containing oligosaccharides. An iterative glycosylation method is established for highly reactive 2-deoxyglycosyl donors on the basis of the DMF modulation concept. This method is effective for 2-deoxy- and 2,6-dideoxythioglycosyl donors, and it opens the gate for the one-pot synthesis of deoxysugar-containing oligosaccharides; NIS = N-iodosuccinimide. Tf = trifluoromethylsulfonyl, NAP = 2-naphthylmethyl, STol = p-tolylthio, Bz = benzoyl.
Highly stereoselective glycosyl-chloride-mediated synthesis of 2-deoxyglucosides
Verma, Ved Prakash,Wang, Cheng-Chung
supporting information, p. 846 - 851 (2013/02/23)
Cl intermediates: The glycosylation of per-O-benzylated 2-deoxy- and 2,6-dideoxythioglycosides, promoted by the combination of para-toluenesulfenyl chloride (p-TolSCl) and silver triflate (AgOTf), furnished the products in high yields and high stereoselec
