Clip-off Chemistry: A New Paradigm for the Design and Synthesis of Molecules and Materials

This article describes a novel synthetic approach called Clip-off Chemistry for obtaining various types of organic molecules through a process of molecular “cutting.” This strategy relies on materials that already incorporate the target molecules within their structure, which are then selectively “clipped off” and released. The covalent organic frameworks (COFs) used in the study are designed in advance from simple molecular precursors, with specific chemical bonds incorporated at strategic positions, such as carbon-carbon double and triple bonds, which can be selectively cleaved.Once the COFs have been synthesized, the next step is the release of the macrocycles. To achieve this, ozone gas is employed as a molecular “scalpel.” This gas breaks the reactive bonds through a process known as ozonolysis, releasing the macrocycles rapidly and efficiently and eliminating the need for slow and complex conventional synthesis routes.Using this strategy, nine different types of macrocycles, some containing up to 162 atoms, were synthesized. These included diverse chemical architectures and a variety of functional groups, such as aldehydes and carboxylic acids, demonstrating the versatility of the technique.Overall, this method paves the way for a new, efficient, and versatile approach to obtaining complex molecules, macromolecules, and materials.