Mild generation of selenolate nucleophiles by thiol reduction of diselenides: convenient syntheses of selenyl-substituted aryl aldehydes

Various selenyl-substituted aryl aldehydes were obtained using dithiothreitol (DTT) as a reducing agent for diselenides in the presence of a base. For electron-deficient haloaryl aldehydes, a weak base, such as K2CO3, performed well. However, for electron-rich haloaryl aldehydes, a stronger base, such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), was required for successful substitution. The selenyl-substitution of heteroaryl substrates were also investigated to obtain satisfactory yields of the desired products.