Citation:
Date Published:
12 2014Abstract:
Copper(I)-zeolites, especially copper(I)-ultra stable Y zeolite (USY), are very efficient heterogeneous catalysts for the coupling of functionalized 1-bromoalkynes and various nitrogen derivatives. Under these conditions, sulfonylated alkyl- or arylamines and various N-heterocycles, such as oxazolidinones or indoles, could be efficiently transformed into the corresponding N-alkynyl derivatives. However, imidazoles gave addition products rather than coupling products. The reaction conditions proved compatible with a variety of functional and protecting groups. Such zeolitic catalysts can be recycled and reused at least five times without significant deactivation. Low catalyst loading could be used (4 mol%) and as low as 0.8 mol% of this heterogeneous copper catalyst still gave good conversion and yields.