Reaction of 2,5-dimethyl-1,3,4-oxadiazole with perfluoro-2-butyne

Intramolecular cycloaddition of fluorinated 1,3,4-oxadiazoles to dienes

“…Donor 1,3,4-oxadiazoles are not prone to cycloaddition with the use of an endo-diene fragment. Thus, 2,5-dimethyl-1,3,4-oxadiazole reacts with perfluorobutyne-2 to form only condensed cycloadduct (5), which is the product of an initial ene reaction followed by the [4 + 2]-cycloaddition of perfluorobutyne-2 to the resulting exo-diene component (Scheme 2) [9].…”

2:1 Adducts Arising from Reactions between Benzynes and 1,3,4-Oxadiazoles

“…1,3,4-Oxadiazoles lacking EWGs have relatively higher lowest unoccupied molecular orbitals (LUMOs) and rarely participate in cycloaddition chemistry; other reaction pathways prevail . For example, 2,5-dimethyl-1,3,4-oxadiazole ( 9 ) reacted with 2 equiv of hexafluoro-2-butyne ( 10 ) to afford product 11 (Figure c) . This reaction is believed to be initiated by nucleophilic attack of a nitrogen atom on the electrophilic alkyne carbon.…”