title: Chemo- and regioselective assembly of polysubstituted pyridines and isoquinolines from isocyanides, arynes, and terminal alkynes.
abstract: We have disclosed a general and efficient synthetic strategy for polysubstituted pyridines and isoquinolines with high chemo- and regioselectivity. In this methodology, 1-alkynyl imines act as the key compound to undergo a sequential alkynyl imine-allenyl imine isomerization/aza-Diels-Alder reaction/aromatization. In the first place, 1-alkynyl imines were formed in situ by a highly selective multicomponent reaction of isocyanides, arynes, and terminal alkynes and reacted with another molecule of arynes or terminal alkynes to furnish target heterocyclic products in a highly efficient and atom-economic manner. On the other hand, we attempted to prepare 1-alkynyl imines by other approaches to undergo a similar reaction sequence to afford polysubstituted pyridines and isoquinolines with a wider range. Different from the first approach, the second approach utilized the preprepared 1-alkynyl imines to introduce the related different substitutents into the final products: arynes or terminal alkynes bearing substituents different from those of 1-alkynyl imines have been successfully applied for the synthesis a wide variety of pyridines and isoquinolines with diversity.
authors.affiliation: Department of Chemistry, Zhejiang University (Xixi Campus), Hangzhou 310028, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Sha
authors.forename: Luling
authors.initials: L
authors.lastname: Wu
authors.forename: Xian
authors.initials: X
authors.lastname: Huang
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D003486:Cyanides / Q000737:chemistry*; D003500:Cyclization; D007546:Isoquinolines / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000480:Alkynes; D003486:Cyanides; D007546:Isoquinolines; D011725:Pyridines