Time Crystal Synthon: The Way to Integrate Cascade Reactions for Advancing Multistep Flow Synthesis

Multistep flow catalytic reactions in organic chemistry integrate multiple sequential organic reactions to enhance cost-efficiency, time management, and labour resources, all while boosting effectiveness and environmental sustainability. Similar to how we select molecular synthons for reactions in retrosynthesis, we can employ time-crystal synthons to integrate catalytic reaction cycles in the development of a reaction pathway. This involves considering individual catalytic reaction steps of cycles as time-consuming events that can be topologically arranged like a clock. This results in a perpetual machine that violates time translational symmetry, leading to the production of a time crystal. This approach involves transferring a single product from one catalytic cycle to a neighbouring reaction cycle, connecting various reaction vessels vertically to establish a ‘cascade’ of reaction cycles. Additionally, catalytic cycles can be integrated by sharing common reaction steps or implementing a metathesis reaction at the junction zone of two neighbouring cycles. Here, the concept of time-crystal synthons facilitates the linear integration of heterogeneous catalytic cycles, step by step, to transfer products through the common reaction medium when modifying conventional flow synthesis. Significantly, this time-crystal synthon-driven multistep approach offers advantages over conventional flow synthesis, as the reaction vessels can be equipped with microwave and photosynthesis methodologies, allowing for the collection of specific products from their respective vessels as needed, providing more options to integrate reactions and enabling flow control using gravity.