Supported Tris-Triazole Ligands for Batch and Continuous-Flow Copper-Catalyzed Huisgen 1,3-Dipolar Cycloaddition Reactions

Catalysts

Gianluigi Albano¹  Antonio Lucci¹  Matteo Pollastrini¹  Alessandro Mandoli¹  Marialuigia Colalillo¹  Fabrizio Oliva¹  Alessandra Pucci¹  Delio Santalucia¹  Claudio Evangelisti²  Marcello Marelli³ 

[1] Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, Pisa 56124, Italy;Istituto di Chimica dei Composti Organometallici (ICCOM), Consiglio Nazionale delle Ricerche (CNR), Via G. Moruzzi 1, Pisa 56124, Italy;Istituto di Scienze e Tecnologie Chimiche “Giulio Natta” (SCITEC), Consiglio Nazionale delle Ricerche (CNR) Via G. Fantoli 16/15, Milano 20138, Italy;

关键词: supported catalysts;    click chemistry;    flow chemistry;    1,2,3-triazoles;    monoliths;    nitrogen ligands;   

DOI  :  10.3390/catal10040434

来源: DOAJ

【 摘 要 】

The lack of supported versions of the tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine (TBTA) ligand, suitable for flow-chemistry applications at scale, prompted us to develop a new route for the immobilization of such tris-triazole chelating units on highly cross-linked polystyrene resins. With this aim, the preparation of the known TBTA-type monomer 3 was optimized to develop a high-yield synthetic sequence, devoid of chromatographic purifications at any stage. Then, bead-type (P7) and monolithic (M7) functional resins were obtained by the easy and scalable suspension- or mold-copolymerization of 3 with divinylbenzene. Both types of materials were found to possess a highly porous morphology and specific surface area in the dry state and could be charged with substantial amounts of Cu(I) or Cu(II) salts. After treatment of the latter with a proper reducing agent, the corresponding supported Cu(I) complexes were tested in the copper-catalyzed alkyne-azide cycloaddition reaction (CuAAC). The immobilized catalysts proved active at room temperature and, in batch and with catalyst loadings as low as 0.6 mol%, afforded quantitative conversions within 20 h. Independent of the alkyne structure, extended use of the supported catalyst in flow was also possible. In the reaction of benzylazide and propargyl alcohol, this allowed a total turnover number larger than 400 to be reached.

【 授权许可】

Unknown