Strategies and Methods for the Synthesis of 2‐Pyrazolines: Recent Developments (2012–2022)

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(12), P. 1934 - 1969

Published: May 22, 2023

Abstract 2‐Pyrazolines are important five‐membered heterocycles, containing two adjacent nitrogen atoms. They can incorporate various functional groups and possess unique biological properties. Moreover, they have been used as useful building blocks. In recent years, the field of 2‐pyrazoline synthesis has experienced enormous progress. Novel strategies developed, many studies reporting improvements or adaptations existing protocols published, giving access to new functionalizations, unexplored structures, and/or enantioselective synthesis. This review summarizes progress made in synthetic methodologies during period from 2012 2022. The functionalization challenges capabilities, scopes limitations reactions, substitution patterns, mechanisms where appropriate, will be discussed.

Language: Английский

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Strategy to Construct Polycyclic Scaffolds via Formal Aza‐Diels‐Alder Reaction of Dihydro‐β‐Carboline with Heterodiene Precursor

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(22), P. 3996 - 4001

Published: July 8, 2023

Abstract The formal aza‐Diels‐Alder reaction of dihydro‐ β ‐carboline with heterodiene mediated by caesium carbonate has been described. This pathway provided a mild approach to functionalized polycyclic frameworks in 41%–91% yields.

Language: Английский

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Synthesis of Functionalized Tetrahydroquinoline Containing Indole Scaffold via Chemoselective Annulation of Aza-ortho-quinone Methide Precursor

ACS Omega, Journal Year: 2023, Volume and Issue: 8(25), P. 22352 - 22360

Published: June 13, 2023

The chemoselective annulation of aza-ortho-quinone methide generated by in situ o-chloromethyl sulfonamide has been achieved with bifunctional acyclic olefin. This efficient approach provides access to the diastereoselective synthesis functionalized tetrahydroquinoline derivatives containing indole scaffolds through inverse-electron-demand aza-Diels-Alder reaction under mild conditions excellent results (up 93% yield, > 20:1 dr). Moreover, this article realized cyclization α-halogeno hydrazone electron-deficient alkene affording tetrahydropyridazine derivatives, which had never reported.

Language: Английский

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Strategy to Construct Functionalized Tetrazepine Derivatives via [4+3] Annulation Reaction of Azomethine Imine with Azadiene Precursor

Chinese Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 43(9), P. 3180 - 3180

Published: Jan. 1, 2023

Tetrazepine derivative exhibits good biological activities.Only a limited method has been devoted to constructing these frameworks date.Therefore, an efficient and novel way was established for the synthesis of functionalized tetrazepine scaffolds through cycloaddition reaction azomethine imine with 1,2-azadiene formed in situ by α-halogeno hydrazones presence KOH.This transformation shows excellent functional group tolerance substrate scope.

Language: Английский

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