Expedient Ni(OTf)₂/visible light photoredox-catalyzed annulation of donor–acceptor cyclopropanes with cyclic secondary amines

Abstract

The annulative coupling of donor-accetor cyclopropanes with cyclic secondary amines is reported using the combination of Ni(OTf)2 and visibile light assisted eosin Y catalysis for tandem C-N and C-C bonds...

Synthesis of Heterocycles from Donor-Acceptor Cyclopropanes: A Five-Year Recap

“…47 Here the solvent, HFIP acts as a hydrogen bond donor producing intermediates such as 89, thus aligning the carbonyls to accept the charge, facilitating the ring opening. 48 The reaction resulted in the formation of pyrrolo tetrahydroisoquinolines of the type 92 with high diastereoselectivity. The mechanism was proposed after several control experiments and is explained along the following lines.…”

“…In 2022, Punniyamurthy and co-workers reported Ni(OTf) 2 and visible-light-assisted eosin Y catalysis for the annulation of DACs with cyclic secondary amines, such as tetrahydroisoquinoline 91 (Scheme 20 ). 48 The reaction resulted in the formation of pyrrolo-tetrahydroisoquinolines 92 with high diastereoselectivity. Control studies led to the following mechanism.…”

Oxidants Controlled C−H Bond Functionalization of N‐Aryltetrahydroisoquinolines: The Construction of the Quaternary Carbon Center and Cleavage of the C−N Bond

“…For example, as early as 2004, Li group achieved an α‐alkynylation of THIQs through copper catalysis in the presence of peroxide [3a] . Recently, the study of α‐functionalization of THIQs is still hot, and based on photocatalysis and electrochemical methods, α‐allenylation, α‐cyanation and tandem annulation were also reported, [3l–o] implying that there is still a lot of research space in the functionalization of THIQs. However, the α‐difunctionalization of THIQs to construct an α‐quaternary carbon center remains relatively rare, even in the presence of excessive oxidants (eq 2) [3j–k] …”

One-pot C–N/C–C bond formation and oxidation of donor–acceptor cyclopropanes with tetrahydroisoquinolines: access to benzo-fused indolizines

“…8 On the other hand, isoquinolines are found as synthetic manifolds in natural products and bio-active molecules. 9 The modification or derivatization to these scaffolds is mainly involved in C–H functionalization of α-C–H bonds. 10 In particular, the oxidative cross-dehydrogenative coupling (CDC) can deliver synthetically important pharmacophores.…”