3 research outputs found
Copper(I)-Catalyzed Three Component Reaction of Sulfonyl Azide, Alkyne, and Nitrone Cycloaddition/Rearrangement Cascades: A Novel One-Step Synthesis of Imidazolidin-4-ones
A novel one-pot azide–alkyne/ketenimine–nitrone cycloaddition sequence that is induced by copper(I) and allows the transformation of sulfonyl azides, alkynes, and nitrones to highly substituted imidazolidin-4-ones is described. The corresponding heterogeneous version utilizing Cu(I)-modified zeolites as recyclable heterogeneous catalysts shows marginally improved yield and diastereoselectivity
Copper-Catalyzed Sulfonyl Azide–Alkyne Cycloaddition Reactions: Simultaneous Generation and Trapping of Copper–Triazoles and −Ketenimines for the Synthesis of Triazolopyrimidines
First
simultaneous generation and utilization of both copper–triazole
and −ketenimine intermediates in copper-catalyzed sulfonyl
azide–alkyne cycloaddition reactions is achieved for the one-pot
synthesis of triazolopyrimidines via a novel copper-catalyzed multicomponent
cascade of sulfonyl azides, alkynes, and azirines. Significantly,
the reaction proceeds under very mild conditions in good yields
Copper-Catalyzed Ring-Expansion Cascade of Azirines with Alkynes: Synthesis of Multisubstituted Pyridines at Room Temperature
The
first intermolecular ring-expansion cascade of azirines with
alkynes for the synthesis of pyridines, enabled by a copper/triethylamine
catalytic system via simultaneous generation and utilization of yne-enamine
and skipped-yne-imine intermediates, is reported. Experimental as
well as computational mechanistic studies revealed that the role of
triethylamine is crucial in deciding the reaction pathway toward the
pyridine products. This process offers a novel, one-step, direct,
and practical strategy for the rapid construction of highly substituted
pyridines under exceedingly mild conditions, and an installed alkyne
functionality