Enantioselective annulation reactions through C(sp2)-H activation with chiral CpxMIII catalysts

Chiral poly(hetero)cyclic compounds are extensively found in numerous bioactive molecules, natural products, and even func-tional materials. Synthesis of this class of molecules follows tedious classical synthetic procedures in general. Recent advancement of the transition-metal-catalyzed directed C-H bond activation fol-lowed by an intra-/intermolecular cyclization reaction provides an upfront approach to the construction of numerous poly(hetero)cy-clic compounds. However, synthesis of chiral annulated products remains challenging. In general, chiral annulated products are syn-thesized by a conventional organocatalytic pathway employing suitable chiral ligand systems. Lack of suitable chiral ligands and dif-ficulties in the design and synthesis of appropriate ligands constrain the exploration of the chemistry. Remarkably, recent advances on chiral transition-metal catalysis and chiral ligand-controlled asym-metric C(sp2)-H bond functionalization chemistry demonstrate a way forward to access chiral annulated products. This review provides an overview of recent advancements in chiral CpxM(III)-catalyzed asymmetric annulation reactions, emphasizing the mecha-nistic understanding of the developed protocols.

Automated summary

Chiral poly(hetero)cyclic compounds are commonly found in bioactive molecules, natural products, and functional materials. The synthesis of these compounds typically involves tedious classical synthetic procedures. However, recent advancements in transition-metal-catalyzed C-H bond activation and cyclization reactions have provided a more efficient approach. Despite these advancements, the synthesis of chiral annulated products remains challenging. This review highlights recent advancements in asymmetric annulation reactions catalyzed by chiral CpxM(III) complexes, focusing on the mechanistic understanding of the developed protocols.