Rhodium(III)-Catalyzed Redox-Neutral Synthesis of Isoquinolinium Salts via C–H Activation of Imines

Abstract

Redox-neutral synthesis of isoquinolinium salts via C-H activation of presynthesized or in situ formed imines and coupling with α-diazo ketoesters has been realized, where a zinc salt promotes cyclization as well as provides a counteranion. Under three-component conditions, both ketone and aldehydes are viable arene sources. The coupling of imines with diazo malonates under similar conditions afforded isoquinolin-3-ones as the coupling product.

Controllable Tandem [3+2] Cyclization of Aromatic Aldehydes with Maleimides: Rhodium(III)-Catalyzed Divergent Synthesis of Indane-Fused Pyrrolidine-2,5-dione

“…However, no H/D exchange was observed on the benzene ring when the same reaction was performed in the presence of N -ethylmaleimide (Scheme b). These results indicate that the reverse C–H activation is much slower than the step following C–H activation, which is similar to our previous results and the related references. , The kinetic isotopic effect (KIE) was determined by two parallel reactions of benzaldehyde and pentadeuterated benzaldehyde with N -methylmaleimide under optimal conditions within 1 h, and the k H / k D ratio was found to be 1.26 (Scheme c; see Table S4 and Figure S3), indicating that the C–H activation may not be involved in the rate-determining step.…”

Comprehensive Strategies for the Synthesis of Isoquinolines: Progress Since 2008

“…Based on the detailed mechanistic studies, authors have formulated the reaction mechanism which is in agreement with the conventional Rh-catalysis (Scheme 213). [225] Again in 2018, Webb et al described Rhodiumcatalyzed isoquinoline synthesis which is similar to the previously reported method by Chu et al [194] The method relies on CÀ H activation/annulation strategy using vinyl acetate 321 as an acetylene equivalent. The methods holds good for wide range of substrates by giving good yields (Scheme 214).…”

“…Based on the detailed mechanistic studies, authors have formulated the reaction mechanism which is in agreement with the conventional Rh‐catalysis (Scheme 213). [225] …”

Síntese, funcionalização e prospecção biológica de fragmentos heterocíclicos baseados em núcleos heteroaromáticos subexplorados

“…Alternativas sintéticas para construção do anel piridona em padrões estruturais do tipo 3-isoquinolinona. (Kanojia et al, 1988;Durola et al, 2006;Allan et al, 2009;Micale et al, 2009;Pati e Liu, 2009;Zheng et al, 2009;Zhang et al, 2011;Che et al, 2013;Fanté et al, 2014;Moni et al, 2015;Kim et al, 2016;Li et al, 2016;Moni et al, 2016;Pilgrim et al, 2016;Silva Junior et al, 2016;Wang, J. et al, 2016;Kaiser et al, 2017;Tian et al, 2018).…”

“…Nestes casos os grupos imidato ou imina atuam como dirigentes da reação e, o reagente diazocetoéster é a fonte dos carbonos C-1 e C-2 da estrutura da 3isoquinolinona (Esquema 16). A utilização de catalisadores de ródio para essas reações é possível quando, imidato ou imina são utilizados como grupo dirigentes, bem como com o uso de diferentes diazocetoésteres (Li et al, 2016;Wang, J. et al, 2016;Tian et al, 2018). No entanto, catálise com cobalto foi apenas descrita para obtenção de 3-isoquinolinonas a partir de aril iminas (Esquema 16) (Kim et al, 2016).…”