Formation of a Hydrogen-Bonded Barbiturate [2]-Rotaxane

Interlocked structures containing
the classic Hamilton barbiturate
binding motif comprising two 2,6-diamidopyridine units are reported
for the first time. Stable [2]-rotaxanes can be accessed either through
hydrogen-bonded preorganization by a barbiturate thread followed by
a Cu+-catalyzed “click” stoppering reaction
or by a Cu2+-mediated Glaser homocoupling reaction.