Academic literature on the topic '3-(2-pyridyl)triazolo[1, 5-a]pyridine'

Masahiro Yoshida of the University of Tokushima described (Tetrahedron Lett. 2008, 49, 5021) the Pt-mediated rearrangement of alkynyl oxiranes such as 1 to the furan 2. Roman Dembinski of Oakland University reported (J. Org. Chem. 2008, 73, 5881) a related zinc-mediated rearrangement of propargyl ketones to furans. The cyclization of aryloxy ketones such as 3 to the benzofuran 4 developed (Tetrahedron Lett. 2008, 49, 6579) by Ikyon Kim of the Korea Research Institute of Chemical Technology is likely proceeding by a Friedel-Crafts mechanism. Sandro Cacchi and Giancarlo Fabrizi of Università degli Studi “La Sapienza”, Roma, observed (Organic Lett. 2008, 10, 2629) that base converted the enamine 5 to the pyrrole 6. Alternatively, oxidation of 5 with CuBr led to a pyridine. Zhuang-ping Zhuan of Xiamen University prepared (Adv. Synth. Cat. 2008, 350, 2778) pyrroles such as 9 by condensing an alkynyl carbinol 7 with a 1,3-dicarbonyl compound. Richard C. Larock of Iowa State University found (J. Org. Chem. 2008, 73, 6666) that combination of an alkynyl ketone 10 with 11 followed by oxidation with I-Cl led to the pyrazole 12. The “click” condensation of azides with alkynes, leading to the 1,4-disubstituted 1,2,3- triazole, has proven to be a powerful tool for combinatorial synthesis. Valery V. Fokin of Scripps/La Jolla and Zhenyang Lin and Guochen Jia of the Hong Kong University of Science and Technology have developed (J. Am. Chem. Soc. 2008, 130, 8923) a complementary approach, using Ru catalysts to prepare 1,5-disubstituted 1,2,3- triazoles. Remarkably, internal alkynes participate, and, as in the conversion of 13 to 15, propargylic alcohols direct the regioselectivity of the cycloaddition. A variety of methods have been put forward for functionalizing pyridines. Sukbok Chang of KAIST described (J. Am. Chem. Soc. 2008, 130, 9254) the direct oxidative homologation of a pyridine N -oxide 16 to give the unsaturated ester 18. Jonathan Clayden of the University of Manchester observed (Organic Lett. 2008, 10, 3567) that metalation of 19 gave an anion that rearranged to 20 with complete retention of enantiomeric excess. Shigeo Katsumura of Kwansei Gakuin University developed (Tetrahedron Lett. 2008, 49, 4349) an intriguing three-component coupling, combining 21, 22, and methanesulonamide 23 to give the pyridine 24.

Peter Wipf at the University of Pittsburgh utilized (J. Org. Chem. 2013, 78, 167) an alkynol-furan Diels-Alder reaction to convert 1 into the hydroxyindole 2. An intramolecular Larock indole synthesis was employed (Angew. Chem. Int. Ed. 2013, 52, 4902) by Yanxing Jia at Peking University for the conversion of aniline 3 to tricyclic indole 4. The reaction of boronodiene 5 with nitrosobenzene to produce pyrrole 6 was reported (Chem. Commun. 2013, 49, 5414) by Bertrand Carboni at CNRS University of Rennes and Andrew Whiting at Durham University. The merger of imine 7 with propargyl amine 8 in the presence of a strong base, leading to pyrrole 9, was disclosed (Org. Lett. 2013, 15, 3146) by Boshun Wan at the Chinese Academy of Sciences. Bin Li and Baiquan Wang at Nankai University found (Org. Lett. 2013, 15, 136) that pyrrole 12 could be prepared by the oxidative annulation of enamide 10 with alkyne 11 via ruthenium catalysis in the presence of copper(II). Naohiko Yoshikai at Nanyang Technological University demonstrated (Org. Lett. 2013, 15, 1966) that N-allyl imine 13 could be cyclized to pyrrole 14 via dehydrogenative intramolecular Heck cyclization. Rhett Kempe at the University of Bayreuth developed (Nature Chem. 2013, 5, 140) a “sustainable” pyrrole synthesis in which iridium complex 17 catalyzed the dehydrogenative coupling of alcohol 15 and phenylalaninol (16) to produce pyrrole 18. In a related process, David Milstein at the Weizmann Institute of Science found (Angew. Chem. Int. Ed. 2013, 52, 4012) that the ruthenium complex 20 effected the transformation of 2-octanol (19) and 16 to furnish pyrrole 21. An alternative ruthenium-catalyzed pyrrole synthesis from readily available components was developed (Angew. Chem. Int. Ed. 2013, 52, 597) by Matthias Beller, allowing for the preparation of 25 from ketone 22, diol 23, and amine 24. Meanwhile, with a bit of hetero-aromatic alchemy, Huw M.L. Davies at Emory University converted (J. Am. Chem. Soc. 2013, 135, 4716) the furan 26 to pyrrole 28 by reaction with triazole 27 under rhodium catalysis. Professor Kempe also developed (Angew. Chem. Int. Ed. 2013, 52, 6326) a method for the synthesis of pyridine 30 from amino alcohol 29 and propanol using an iridium catalyst closely related to 17.

Nabyl Merbouh and Robert Britton of Simon Fraser University developed (Eur. J. Org. Chem. 2013, 3219) a general route to a 2,5-disubstituted furan 3 by taking advantage of the ready α-chlorination of an aldehyde 1, followed by coupling with a ketone eno­late 2. Jérôme Waser of the Ecole Polytechnique Fédérale de Lausanne used (Angew. Chem. Int. Ed. 2013, 52, 6743) 5 to oxidize the allene 4 to the furan 6. Qian Zhang and Xihe Bi of Northeast Normal University used (Angew. Chem. Int. Ed. 2013, 52, 6953) Ag catalysis to prepare the pyrrole 9 by coupling the alkyne 7 with the isonitrile 8. Aiwen Lei of Wuhan University reported (Angew. Chem. Int. Ed. 2013, 52, 6958) similar results. Professor Lei also developed (Chem. Commun. 2013, 49, 5853) the Pd-catalyzed oxidation of the allyl imine 10 to the pyrrole 11. Kamal K. Kapoor of the University of Jammu reduced (Tetrahedron Lett. 2013, 54, 5699) the Michael adduct 12 to the pyrrole 13 with triethyl phosphite. Edgar Haak of the Otto-von-Guericke-Universität, Magdeburg condensed (Eur. J. Org. Chem. 2013, 7354) the alkynyl carbinol 14 with aniline to give the N-phenyl pyrrole 15. Jean Rodriguez and Thierry Constantieux of Aix-Marseille Université prepared (Eur. J. Org. Chem. 2013, 4131) the pyridine 18 by combining the ketone 16 and the unsaturated aldehyde 17 with NH4OAc. Teck-Peng Loh of the University of Sciences and Technology of China and Nanyang Technological University found (Angew. Chem. Int. Ed. 2013, 52, 8584) that TMEDA was an effective organocatalyst for the assembly of the pyridine 21 from 19 and 20. Andrew D. Smith of the University of St Andrews showed (Angew. Chem. Int. Ed. 2013, 52, 11642) that the pyridyl tosylate 24, avail­able by the combination of 22 and 23, readily coupled with both carbon and amine nucleophiles. In a related development, D. Tyler McQuade of Florida State University prepared (Org. Lett. 2013, 15, 5298) the 2-bromopyridine 26 from the alkylidene malononitrile 25. Two versatile approaches to substituted indoles were recently described. David F. Wiemer of the University of Iowa cyclized (J. Org. Chem. 2013, 78, 9291) the Stobbe product 27 to the 3-bromo indole 28.