title: The first example of palladium-catalyzed cascade amidine arylation-intramolecular ester amidation for the synthesis of hypoxanthines: application to the synthesis of 8-azanebularine analogues.
abstract: 8-Azanebularine analogues display interesting antiviral, antitumour and biochemical activities. However, typical glycosylation of 8-azapurines always resulted in the desired products in low yields due to the lack of stereo- and regioselectivity of the glycosylation reaction. Herein, a concise synthetic route toward 8-azanebularine analogues has been developed. Key steps involve a copper-catalyzed 1,3-dipolar cycloaddition of a 1-β-azido sugar moiety with ethyl 3-bromopropiolate and a palladium-catalyzed cascade amidine arylation-intramolecular ester amidation reaction to build the hypoxanthine structural motif. This protocol affords a facile methodology for the synthesis of a series of novel 8-azanebularine analogues from the readily accessible 1-β-azido sugar moiety under mild conditions.
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Henan Province 450001, China. wujie@zzu.edu.cn chjsong@zzu.edu.cn changjunbiao@zzu.edu.cn.
authors.forename: Wu
authors.initials: W
authors.lastname: Yang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Henan Province 450001, China. wujie@zzu.edu.cn chjsong@zzu.edu.cn changjunbiao@zzu.edu.cn.
authors.forename: Haoran
authors.initials: H
authors.lastname: Ma
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Henan Province 450001, China. wujie@zzu.edu.cn chjsong@zzu.edu.cn changjunbiao@zzu.edu.cn.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Henan Province 450001, China. wujie@zzu.edu.cn chjsong@zzu.edu.cn changjunbiao@zzu.edu.cn.
authors.forename: Jingwen
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Henan Province 450001, China. wujie@zzu.edu.cn chjsong@zzu.edu.cn changjunbiao@zzu.edu.cn.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Henan Province 450001, China. wujie@zzu.edu.cn chjsong@zzu.edu.cn changjunbiao@zzu.edu.cn.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Yang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Henan Province 450001, China. wujie@zzu.edu.cn chjsong@zzu.edu.cn changjunbiao@zzu.edu.cn.
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Henan Province 450001, China. wujie@zzu.edu.cn chjsong@zzu.edu.cn changjunbiao@zzu.edu.cn.
authors.forename: Chuanjun
authors.initials: C
authors.lastname: Song
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Henan Province 450001, China. wujie@zzu.edu.cn chjsong@zzu.edu.cn changjunbiao@zzu.edu.cn.
authors.forename: Junbiao
authors.initials: J
authors.lastname: Chang
mesh_terms: D000578:Amidines / Q000737:chemistry*; D002384:Catalysis; D004952:Esters / Q000737:chemistry*; D007042:Hypoxanthines / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D010165:Palladium / Q000737:chemistry*; D011684:Purine Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D012263:Ribonucleosides / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C520167:8-azanebularine; D000578:Amidines; D004952:Esters; D007042:Hypoxanthines; D011684:Purine Nucleosides; D012263:Ribonucleosides; D010165:Palladium