Theoretical study of Re(IV) and Ru(II) bis-isocyanide complexes and their reactivity in cycloaddition reactions with nitrones

► ReIV is predicted to be a good activator of CNR towards cycloadditions with nitrones. ► RuII is not expected to be an efficient activator of CNR in cycloaddition reactions. ► The mechanism of the reactions is concerted asynchronous. ► Cycloaddition of the second nitrone should occur harder than that of the first one. ► An application of non- or low-polar solvents is recommended for cycloadditions to CNR.