Heteroditopic Rebek's Imide Directs the Reactivity of Homoditopic Olefins within Desolvated Quaternary Assemblies in the Solid State

A rare single crystal to single crystal transformation leads to a [2+2] photodimerization of homoditopic olefins (trans-1,2-bis(4-pyridyl)ethylene) assembled and preorganized within hydrogen-bonded quaternary complexes by using Rebek's imide. In this way a rctt-tetrakis(4-pyridyl)cyclobutane (see picture) was obtained stereospecifically in up to 100 % yield.