Recovery of Artemisinin from a Complex Reaction Mixture Using Continuous Chromatography and Crystallization

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Recovery of Artemisinin from a Complex Reaction Mixture Using Continuous Chromatography and Crystallization

Articles ASAP (As Soon As Publishable)
Publication Date (Web): May 8, 2015 (Article)
DOI: 10.1021/acs.oprd.5b00048
*E-mail: seidel-morgenstern@mpi-magdeburg.mpg.de. Tel.: +49-(0)391-6110 401. Fax: +49-(0)391-6110 521.
Artemisinin, a secondary metabolite of sweet wormwood, is the basis for the production of the most effective antimalarial drugs. Since the amount of artemisinin currently produced from…

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Cyclopentyl methyl ether-NH4X: a novel solvent/catalyst system for low impact acetalization reactions

Green Chem., 2015, Advance Article

*Corresponding authors
aDipartimento di Chimica e Farmacia, Università di Sassari, via Vienna 2, 07100 – Sassari, Italy
E-mail: ugo@uniss.it
Green Chem., 2015, Advance Article

DOI: 10.1039/C5GC00465A

Cyclopentyl methyl ether and ammonium salts provide an environmentally friendly reaction medium for the synthesis of acetals.
Cyclopentyl methyl ether-NH4X: a novel solvent/catalyst system for low impact acetalization reactions
Cyclopentyl methyl ether, a low impact ether forming a positive azeotrope with water, was successfully employed as a solvent in the synthesis of 1,3-dioxanes and 1,3-dioxolanes carried out under Dean-Stark conditions by the acetalization of aliphatic and aromatic aldehydes or ketones, employing ammonium salts as environmentally friendly acidic catalysts.

Enantioselective α-amination of 1,3-dicarbonyl compounds in batch and flow with immobilized thiourea organocatalysts

Enantioselective α-amination of 1,3-dicarbonyl compounds in batch and flow with immobilized thiourea organocatalysts

*Corresponding authors
aInstitute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona, Spain
bDepartament de Química Orgànica, Universitat de Barcelona, 08080 Barcelona, Spain
Green Chem., 2015, Advance Article

A PS-immobilized thiourea catalyses the enantioselective [small alpha]-amination of dicarbonyl compounds at room temperature. It is not deactivated by azodicarboxylate reagents, allowing multiple recycling in batch as well as use in flow (21 min residence time).
DOI: 10.1039/C5GC00496A

A polymer-supported bifunctional thiourea organocatalyst (PS-TU) has been prepared and successfully used in the enantioselective α-amination of 1,3-dicarbonyl compounds with azodicarboxylates. In contrast to homogeneous thioureas, PS-TU is not irreversibly deactivated by the azodicarboxylate reagents, and simple washing with triethylamine between runs has allowed the reuse (9 cycles) of the PS-TU catalyst. The α-amination mediated by PS-TU has also been adapted to perform the enantioselective amination (93% ee) of ethyl 2-oxocyclopentanecarboxylate in continuous flow (7.5 h operation, 21 min residence time, TON = 37).