Calcium carbonate as heterogeneous support for recyclable organocatalysts

• Published in: Journal of catalysis 2021-01, Vol.393, p.107-115
• Main Authors: Lizandara-Pueyo, Carlos, Fan, Xinyuan, Ayats, Carles, Pericàs, Miquel A.
• Format: Article
• Language: English
• Subjects: Asymmetric catalysis; Calcium carbonate; Catalyst recycling; Click chemistry; Continuous flow processes; Solid-supported catalysis; Surface functionalization
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2020.11.013

[Display omitted] •The CaCO3 particles are evaluated in the heterogenization of homogeneous asymmetric catalysts for the first time.•The CaCO3-supported Jørgensen-Hayashi catalysts are developed for asymmetric Michael additions.•Recycling of CaCO3 heterogeneous catalysts are achieved by condition optimization.•CaCO3 heterogeneous catalysts are adapted in catalytic continuous flow processes. The controlled synthesis of calcium carbonate particles surface-functionalized with azido groups and its subsequent copper-catalyzed alkyne-azide cycloaddition (CuAAC) reactions with organocatalysts bearing alkyne anchors allowed the preparation of novel catalytic materials. A calcium carbonate-supported α,α-diarylprolinol silyl ether prepared in this manner catalyzes Michael addition of aldehydes to trans-β-nitrostyrenes with very high diastereo- and enantioselectivity. The immobilized catalyst can be recovered by simple decantation and reused. In addition, this heterogeneous catalytic system can also be adapted to continuous-flow operation, affording a five-fold productivity increase in comparison with the batch process.