Front Cover Picture: Rapid (Deuterio)difluoromethylation of Heteroatoms Using R‐22 Gas: A Demonstration of Flow Chemistry in Suppressing Intrinsic Reaction Pathways (Adv. Synth. Catal. 21/2024)

The front cover features a Tarot-style card titled “THE FLOW”. A sage seated by a cascading stream (symbolizing a flow system) holds deuterium and hydrogen atoms and determines the reaction pathway for ClCF2H molecules in the sky. By varying the addition and mixing sequences within a flow system, ClCF2H gas can undergo an SN2 reaction with heteroatom anions to produce X-CF2H products, or be selectively converted into difluorocarbenes for a carbene-based fragment coupling, yielding X-CF2D products. More details can be found in Communication by Wai Chung Fu and co-workers (H. C. Leung, T. C. Lee, W.-T. Wong, W. C. Fu, Adv. Synth. Catal. 2024, 366, XXXX–XXXX; DOI: 10.1002/adsc.202400826)