Publication – Copper(I)-catalyzed azide–alkyne cycloadditions in microflow: Catalyst activity, high-T operation, and an integrated continuous copper scavenging unit

ChemSusChem. doi: 10.1002/cssc.201200323

• Alvaro Carlos Varas, Dr. Timothy Noël, Dr. Qi Wang, Prof. Dr. Volker Hessel*
• Eindhoven University of Technology, Micro Flow Chemistry & Process Technology, Den Dolech 2, Helix, STW 2.49, P.O. Box 513, 5600 MB Eindhoven, The Netherlands

The Asia FLLEX module was used as a copper scavenging/extracting unit.

Abstract: A continuous-flow synthesis for the Cu^I-catalyzed azide–alkyne cycloaddition reaction using [Cu(phenanthroline)(PPh₃)₂]NO₃ as a homogeneous catalyst is developed (up to 92 % isolated yield). Elevated temperatures allow achieving full conversions and using lower catalyst loadings. Residual copper in the triazole compound is efficiently removed via an inline extraction process, employing aqueous EDTA as a copper scavenger.

An Asia system and the Asia FLLEX module was used as a copper scavenging/extracting unit for this paper.