Enantioselective Reaction of 2H‐Azirines

Abstract

2H‐Azirines are useful precursors for the synthesis of a variety of chiral aziridine and amine derivatives with a range of biological activities. Owing to the ring strain and the presence of a C=N double bond, 2H‐azirines are more reactive than other types of ketimine, and undergo a range of enantioselective reactions, including reduction and Diels–Alder reactions, as well as nucleophilic addition to the C=N double bond. Therefore, the enantioselective reactions of 2H‐azirines has become a hot topic, in particular within the last few years. In this Minireview, we focus on the enantioselective reactions of 2H‐azirines by using catalytic or stoichiometric amounts of chiral additives, the reaction mechanisms, and the applications of these reactions of 2H‐azirines and related compounds in organic synthesis.

2H‐Azirines: Recent Progress in Synthesis and Applications

“…Along this line, 2H ‐azirine can be used as a good reactant with untaturated compounds for the construction of aza‐heterocycles via [3+n] cycloaddition or nucleophilic addition/cyclization in distinguishing processes. There are recent reviews referring to 2H ‐azirines, including reviews of advances in 2H ‐azirine chemistry, [7] synthesis of various functionalized 2H ‐azirines, [8] computational studies on 2H ‐azirines, [9] and enantioselective reaction of 2H ‐azirines [10] . This review represents an analysis of studies devoted to the search for some new synthetic methods of 2H ‐azirines, novel reactions based on 2H ‐azirines for the synthesis of numerous heterocycles and acyclic compounds, and especially covers the period from 2019 to 2023.…”

Regioselective Transition Metal-Free Catalytic Ring Opening of 2H-Azirines by Phenols and Naphthols; One-Pot Access to Benzo- and Naphthofurans

“…23 Apart from that, enantioselective reactions by 2H-azirines are also known. 27 Although a number of methods are available to construct benzofuran scaffolds from different chemical entities, 14,28 to the best of our knowledge, the use of the regioselective ring opening strategy of 2H-azirines has never been reported to synthesize benzofurans. In the early days, Pavel.…”

“…Previously, Jiang et al (in 2014) introduced the ring expansion metal-free strategy to synthesize pyridines using 3 equiv of DBU . Apart from that, enantioselective reactions by 2 H -azirines are also known . Although a number of methods are available to construct benzofuran scaffolds from different chemical entities, , to the best of our knowledge, the use of the regioselective ring opening strategy of 2 H -azirines has never been reported to synthesize benzofurans.…”

Catalytic Enantioselective Synthesis of N,N‐Acetals from α‐Dicarbonyl Compounds Using Chiral Imidazoline‐Phosphoric Acid Catalysts

“…[16] The enantioselective reactions of 2H-azirine as a ketimine with pyrazole or indoline-2-one were reported by Zhang, [17] and Liu and Feng's group. [18] Wang and co-workers reported the enantioselective tandem cyclization of alkyne, amine, and indole using chiral phosphoric acid catalysts. [19] Lin and Duan [20] and Li and co-workers [21] independently reported the enantioselective formation of N,N-acetals between ketimines derived from isatins with amines or triazoles using chiral thiourea catalysts.…”