Transition Metal Promoted Cascade Heterocycle Synthesis through C−H Functionalization

Abstract

Sequential,d omino and tandem reactions could be defined as as equence of synthetic transformationst hat occur one after the other,i nt he same reaction flask. This Review highlights recent advances at the overlap of two worlds:t ransition-metal mediated CÀHa ctivation as at rigger of cascade reaction, for the heterocycles synthesis. To shed some light on this intricate "middle-earth",f ocus was put on the reactionm echanismr ather than the typeo f metal or the chronologicalo rder of the reaction. The aim is to separate, and then highlight, the true domino reactions initiatedb yC ÀHa ctivation, compared to other examples of CÀHf unctionalization for heterocycle syntheses.

20 Years of Forging N-Heterocycles from Acrylamides through Domino/Cascade Reactions

“…Over the last two decades, transition metal-catalyzed cascade sequences were intensively investigated for the rapid construction of poly(hetero)cyclic compounds. 78,79 A few of them include several bond-forming steps involving acrylamide derivatives as substrates. To date, all the methodologies described are involving late-stage transition metals.…”

Microwave-Assisted Synthesis of Quinazolines and Quinazolinones: An Overview

“…Although the aforementioned reactions are considered as the most important transition-metal catalyses, a plethora of vital reactions can be effectively catalyzed by various transition metals including reductive elimination, oxidative addition, and transmetallation. Transition metal catalysis has also found extensive applications in the convenient and efficient synthesis of a wide variety of heterocyclic systems (Ma et al, 2017;Ramanathan and Liu, 2017;Tiwari and Bhanage, 2017;Chatterjee et al, 2018;Saikia et al, 2018;Chen et al, 2020;Debabrata et al, 2020;Ghosh et al, 2020;Janardhanan et al, 2020;Jiang et al, 2020;Kanwal et al, 2020;Kojima and Matsunaga, 2020;Li and Zhang, 2020;Nagata and Obora, 2020;Neto and Zeni, 2020a,b;Pal et al, 2020;Ratmanova et al, 2020;Sahiba and Agarwal, 2020;Sonawane et al, 2020;Xuan et al, 2020). However, the literature survey revealed only an example of zinc (Shi et al, 2004), a limited number of iron-catalyzed (Melvin et al, 1992;Valderrama et al, 1999;Kanth et al, 2006;Yin et al, 2012;Gopalaiah et al, 2017Gopalaiah et al, , 2019Raut and Bhanage, 2017;Eidi et al, 2018), and relatively more copper-catalyzed reactions, leading to the synthesis of quinazoline and quinazolinone derivatives (Melvin et al, 1992;Chatterjee et al, 2018;Potuganti et al, 2018;Liang et al, 2019;Rodrigues et al, 2019;Donthibo...…”

Expedient Synthesis of Bridged Bicyclic Nitrogen Scaffolds via Orthogonal Tandem Catalysis

“…[11] Thec ombination of CÀCb ond formation via unactivated C(sp 3 )-H functionalization with other catalytic reactions in tandem catalysis has received little attention, despite its attractiveness. [12][13][14] Moreover,f or the construction of challenging bridged bicycles it is not known. This enables an expedient synthesis of 7-alkylidenenormorphans provided that high levels of regio-and diastereoselectivities can be obtained.…”