Cascade reactions in crystals through cation–π-controlled reorientation on exposure to HCl gas†
Abstract
Exposure of 4-azachalcones to HCl gas produced the corresponding HCl salts with a head-to-tail stacked alignment, irradiation of which produced the corresponding syn-HT dimers with high regio- and stereoselectivities, thus showing the effectiveness of the cascade process in crystals.