Recent Advances in the Construction of Nitrogen-Containing Heterocycles via Trapping Organocopper(I) Intermediates

Intramolecular Nitrone Interrupted Click Reaction

“…3 One of these approaches includes the trapping of the transient Cutriazolide intermediate involved in this reaction with carbonand/or heteroatom-centered electrophiles, which has been coined as the interrupted click reaction. 4 The early endeavors in this context appeared from the Zhu 5 and Hsung 6 groups, who trapped the Cu-triazolide intermediate with iodinium and allyl cations, leading to the C−I and C−C bond formations, respectively. Subsequently, various other electrophiles such as alkyl, aryl, acyl, and alkynyl diazoalkanes, N-tosylhydrazones, and CF 3 -, S-, Se-, and N-based electrophiles have been explored to extend the potential of this strategy to synthesize 1,4,5-trisubstituted 1,2,3-triazoles.…”

“…The early endeavors in this context appeared from the Zhu and Hsung groups, who trapped the Cu-triazolide intermediate with iodinium and allyl cations, leading to the C–I and C–C bond formations, respectively. Subsequently, various other electrophiles such as alkyl, aryl, acyl, and alkynyl diazoalkanes, N-tosylhydrazones, and CF 3 -, S-, Se-, and N-based electrophiles have been explored to extend the potential of this strategy to synthesize 1,4,5-trisubstituted 1,2,3-triazoles. − …”

“…This has inspired them to devise innovative strategies and postfunctionalization methods, sometimes in a cascade fashion, in order to forge the triazole containing poly­(hetero)­cyclic compounds . One of these approaches includes the trapping of the transient Cu-triazolide intermediate involved in this reaction with carbon- and/or heteroatom-centered electrophiles, which has been coined as the interrupted click reaction . The early endeavors in this context appeared from the Zhu and Hsung groups, who trapped the Cu-triazolide intermediate with iodinium and allyl cations, leading to the C–I and C–C bond formations, respectively.…”

An Alkyne–Isocyanide Cycloaddition/Boulton-Katritzky Rearrangement/Ring Expansion Reaction: Access to 9-Deazaguanines

“…The electrophilic trapping of organocopper­(I) intermediates generated in situ in copper­(I)-catalyzed cycloaddition reactions has attracted broad interests in organic community for the development of novel cascade reactions . Many excellent examples have been described through intermolecular or intramolecular trapping of the organocopper­(I) intermediates in alkyne–isocyanide [3 + 2] cycloaddition, azide–alkyne [3 + 2] cycloaddition, and Kinugasa reaction with varied electrophilic groups or reagents .…”