A Click Chemistry Approach to 5,5′-Disubstituted-3,3′-Bisisoxazoles from Dichloroglyoxime and Alkynes: Luminescent Organometallic Iridium and Rhenium Bisisoxazole Complexes

5,5′-Disubstituted-3,3′-bisisoxazoles
are prepared
in one step by the dropwise addition of aqueous potassium hydrogen
carbonate to a mixture of dichloroglyoxime and terminal alkynes. The
reaction exhibits a striking preference for the 5,5′-disubstituted
3,3′-bisisoxazole over the 4,5′-regioisomer. Organometallic
iridium and rhenium bisisoxazole complexes are luminescent with emission
wavelengths varying depending upon the identity of the 5,5′-substituent
(phenyl, butyl).