Ethynyl π-extended 2, 5-diphenyl-1, 3, 4-oxadiazoles and 2-phenyl 5-(2-thienyl)-1, 3, 4-oxadiazoles: synthesis, X-ray crystal structures and optical properties

G Hughes, D Kreher, C Wang, AS Batsanov…

Index: Hughes, Gregory; Kreher, David; Wang, Changsheng; Batsanov, Andrei S.; Bryce, Martin R. Organic and Biomolecular Chemistry, 2004 , vol. 2, # 22 p. 3363 - 3367

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Citation Number: 27

Abstract

2-(4-tert-Butylphenyl)-5-(4-ethynylphenyl)-1, 3, 4-oxadiazole 1 reacts with a series of heteroaryl iodides under standard Sonogashira cross-coupling conditions (Pd [PPh3] 2Cl2, CuI, triethylamine, THF) to yield products 2a–g in 40–79% yields (heteroaryl= 2-pyridyl, 3- pyridyl, 4-pyridyl, 2-pyrazyl, 5-bromo-2-pyrimidyl, 2-thienyl and 3-thienyl, respectively). Compound 2f was lithiated followed by electrophilic iodination (BuLi, perfluorohexyl ...