Diels–Alder Reactions of 1,2-Dihydropyridines: An Efficient Tool for the Synthesis of Isoquinuclidines

Abstract

The Diels–Alder reaction of 1,2-dihydropyridines with different dienophiles is a well-established and straightforward method for the synthesis of isoquinuclidines. Nevertheless, the enantioselective preparation of isoquinuclidines using organocatalysts or organometallic catalysts is rather unexplored. This succinct review offers readers an overall perspective of the most important recent developments and concepts related to this topic.1 Introduction2 Asymmetric Diels–Alder Reaction of 1,2-Dihydropyridines2.1 Transition-Metal-Catalyzed Reactions2.2 Organocatalyzed Reactions3 Diels–Alder Reaction of 1,2-Dihydropyridines in the Synthesis of Biologically Valuable Compounds4 Conclusion

Enantio- and Diastereoselective Two-Pot Synthesis of Isoquinuclidines from Glutaraldehyde and N-Aryl Imines with DFT Calculations

“…Given such potential importance, the development of methods for the asymmetric synthesis of isoquinuclidine has gained much interest and reviewed recently . More strictly, synthetic efforts to this unit mainly involve atom-economic [4+2] cycloadditions that can be broadly divided into two main categories: (i) a direct catalytic asymmetric aza-Diels–Alder reaction between cyclohexen-1-one and imines (path 1, Scheme a) and (ii) a asymmetric Diels–Alder reaction of 1,2-dihydropyridines (DHPs) with activated alkene as a dienophile (path 2, Scheme a) . In particular, the catalytic enantioselective Diels–Alder reaction between 1,2-DHP and a suitable dienophile is the most explored method to access isoquinuclidine (eq 1, Scheme ).…”

Theoretical Analysis of the Heterocyclic [4+2] Cycloaddition Between Pyridinium Ion and Enol Ether

“…[2b] Dearomative [4 + 2] cycloaddition of pyridine derivatives with alkenes could also be an attractive approach for syntheses of poly-functionalized aminocyclohexane derivatives. However, whereas [4 + 2] cycloadditions of 1,2-dihydropyridine, [3] 2-pyridone, [4] and isoquinolines [5] have been developed as useful methods, the reaction of pyridines was limited to just a few examples of special substituted pyridines. [6,7] One of the pioneering works of [4 + 2] cycloaddition of pyridines was reported by Falck et al in 1990.…”

Green Synthesis of Poly‐Substituted Pyrano[4,3‐b]quinoline‐1,9‐(5H)‐dione Derivatives Using Solid Acid as Catalyst in Water

“…Owing to their biological importance, these dihydropyridine analogs attract the attention of synthetic chemists. In the past several decades, many methodologies for the synthesis of dihydropyridine compounds have been reported . In this regard, the pyranodihydropyridine derivatives should have many special biological and pharmacological activities and the exploration of a versatile strategy for the preparation of them would be highly favorable …”