title: Ultrasonic Synthesis, Molecular Structure and Mechanistic Study of 1,3-Dipolar Cycloaddition Reaction of 1-Alkynylpyridinium-3-olate and Acetylene Derivatives.
abstract: Regioselectively, ethyl propiolate reacted with 1-(propergyl)-pyridinium-3-olate to give two regioisomers; ethyl 4-oxo-8-(prop-2-ynyl)-8-aza-bicyclo(3.2.1)octa-2,6-diene-6-carboxylate 4, ethyl 2-oxo-8-(prop-2-ynyl)-8-aza-bicyclo(3.2.1)octa-3,6-diene-6-carboxylate 5 as well as ethyl 2,6-dihydro-6-(prop-2-ynyl)furo(2,3-c)pyridine-3-carboxylate 6. The obtained compounds were identified by their spectral (IR, mass and NMR) data. Moreover, DFT quantum chemical calculations were used to study the mechanism of the cycloaddition reaction. The regioselectivity was explained using transition state calculations, where the calculations agreed with the formation of products 4 and 5 in almost the same ratio. The reaction was also extended for diphenylaceylene as dipolarophile to give only two products instead of three.
authors.affiliation: Department of Chemistry, Faculty of Science, Taibah University, Yanbu branch, Yanbu 00000, Saudi Arabia. asmaa_aboelnaga77@yahoo.com.|Department of Chemistry, Faculty of Women for Arts, Science and Education, Ain Shams University, Heliopolis, Cairo 11757, Egypt. asmaa_aboelnaga77@yahoo.com.
authors.forename: Asmaa
authors.initials: A
authors.lastname: Aboelnaga
authors.affiliation: Department of Chemistry, Faculty of Science, Taibah University, Yanbu branch, Yanbu 00000, Saudi Arabia. Mohamedhaggar@gmail.com.|Department of Chemistry, Faculty of Science, Alexandria University, P. O. Box 426, Ibrahimia, Alexandria 21321, Egypt. Mohamedhaggar@gmail.com.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Hagar
authors.affiliation: Department of Chemistry, Faculty of Science, Alexandria University, P. O. Box 426, Ibrahimia, Alexandria 21321, Egypt. saied1soliman@yahoo.com.|Department of Chemistry, College of Science &amp; Arts, King Abdulaziz University, P. O. Box 344, Rabigh 21911, Saudi Arabia. saied1soliman@yahoo.com.
authors.forename: Saied M
authors.initials: SM
authors.lastname: Soliman
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry*; D061565:Cycloaddition Reaction; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D013816:Thermodynamics; D000069453:Ultrasonic Waves
chemical_list: D000114:Acetylene
keywords: 1,3-dipolar cycloaddition; molecular structure; reaction mechanism; ultrasonic synthesis