title: Modulating the reactivity of functionalized N,S-ketene acetal in MCR: selective synthesis of tetrahydropyridines and thiochromeno[2,3-b]pyridines via DABCO-catalyzed tandem annulation.
abstract: An efficient and straightforward three-component synthetic protocol was developed to synthesize 1,2,3,4-tetrahydropyridine derivatives or thiochromeno[2,3-b]pyridine derivatives from β-aroylthioacetanilides or β-(2-haloaroyl)thioacetanilides, aldehydes, and aroyl acetonitriles via DABCO-catalyzed tandem [3 + 2 + 1] annulation and S(N)Ar reaction. This synthetic approach has the prominent features of high chemo-, stereo- (or enantio-), and unusual regioselectivity. In the domino processes, at least seven reactive sites were involved, and up to three covalent bonds and one functionalized pyridine ring were generated. This facile and efficient reaction is a quite general for the preparation of tetrahydropyridine derivatives or thiochromeno[2,3-b]pyridine derivatives.
authors.affiliation: State Key Laboratory Base of Eco-Chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao 266042, P. R. China. wenlirong@qust.edu.cn
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Wen
authors.forename: Yong-Jie
authors.initials: YJ
authors.lastname: Shi
authors.forename: Guang-Yuan
authors.initials: GY
authors.lastname: Liu
authors.forename: Ming
authors.initials: M
authors.lastname: Li
mesh_terms: D000080:Acetals / Q000737:chemistry*; D000097:Acetonitriles / Q000737:chemistry*; D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D002839:Chromans / Q000138:chemical synthesis* / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry*; D006574:Heterocyclic Compounds, 2-Ring / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: C575056:1,4-diazabicyclic(2,2,2)octane; D000080:Acetals; D000097:Acetonitriles; D000447:Aldehydes; D002839:Chromans; D005030:Ethylenes; D006574:Heterocyclic Compounds, 2-Ring; D007659:Ketones; D011725:Pyridines; C575055:thiochromeno(2,3-b)pyridine; C008223:ketene