α-Tertiary Propargylamine Synthesis via KA2-Type Coupling Reactions under Solvent-Free CuI-Zeolite Catalysis

The potential of copper(I)-zeolite catalysis was evaluated in the three-component KA(2)-coupling mediated synthesis of a-tertiary propargylamines. Our archetypal copper(I)-doped zeolite Cu-I-USY proved to be efficient under ligand- and solvent-free conditions at 80 degrees C. Usable up to four times, this catalytic material enables the coupling of diverse ketones, alkynes, and amines with a broad functional group tolerance. A decarboxylative and a desilylative version, respectively, involving an alkynoic acid and trimethylsilylacetylene as alkyne surrogates, was also set up to bypass selectivity issues and/or to access a-tertiary propargylamines that are unattainable under standard KA(2) conditions. Interestingly, the KA(2)-type coupling reactions were successfully linked to other Cu-I-catalyzed reactions, thus resulting in sequential one-pot processes under full Cu-I-USY catalysis.

Automated summary

The potential of copper(I)-zeolite catalysis was evaluated in the synthesis of α-tertiary propargylamines via a three-component KA(2)-coupling, showing efficiency and broad functional group tolerance. In addition, decarboxylative and desilylative methods were successfully used to bypass selectivity issues and achieve sequential one-pot processes under full copper(I)-zeolite catalysis.