2026/01/01 by Neil R. Judge, Andreu Tortajada, Eva Hevia · 1 voice
Chemistry · #Coordination Chemistry and Organometallics #Catalytic C–H Functionalization Methods #Organometallic Complex Synthesis and Catalysis
paper · doi:10.1039/d6cs00275g
Typified by the Lochmann-Schlosser superbase, the use of Group 1 alkali-metal alkoxides as additives to enhance the reactivity of s-block organometallic reagents is a well-established concept in organic synthesis. However, for decades the origin of this activating effect remained unclear, and the constitution of the organometallic species involved was poorly understood. More recent studies have revealed that mixed-metal, mixed-aggregate complexes constitute the active species in these transformations. By enabling bimetallic cooperation, such combinations can display enhanced reactivity and distinct regioselectivities compared to their monometallic counterparts. This Tutorial Review highlights recent advances in this field, including the use of alkali-metal alkoxides in combination with organozinc and organomagnesium reagents to unlock new applications in deprotonative metalation and metal-halogen exchange reactions. Particular emphasis is placed on developing a mechanistic understanding of how these heterobimetallic mixtures operate. Focusing on recent synthetic studies on arene functionalisation, this Review also showcases the key role of coordination effects in finely tuning the regioselectivity of these transformations.