Highly Active Cellulose-Supported Poly(hydroxamic acid)-Cu(II) Complex for Ullmann Etherification

Ullmann-Type N-, S-, and O-Arylation Using a Well-Defined 7-Azaindole-N-oxide (7-AINO)-Based Copper(II) Catalyst: Scope and Application to Drug Synthesis

An air-stable, robust, and well-defined copper(II)-7-azaindole-N-oxide-based catalyst [Cu2II(7-AINO)4] (abbreviated as Cu(II)-7-AINO) has been demonstrated as an efficient catalyst for various Ullmann-type coupling reactions. This easily prepared and cost-effective catalyst facilitates the arylation and heteroarylation of diverse N-, S-, and O-nucleophiles, including azoles, aminoazoles, (hetero)arylthiols, and phenols. Notably, they also exhibit substantial compatibility with a wide range of functional groups. Furthermore, the catalyst demonstrates significant selectivity for -NH sites of aminoazoles and -SH sites of aminothiophenols over -NH2 sites in both cases, enhancing its versatility. Exploiting the catalyst's chemo- and regioselective properties, we have successfully demonstrated the applicability of our methodology in synthesizing various drug molecules. Specifically, Epirizole analogue, Nilotinib, and Vortioxetine were successfully synthesized using our protocol.

Synthesis and characterization of highly efficient and recoverable Cu@MCM-41-(2-hydroxy-3-propoxypropyl) metformin mesoporous catalyst and its uses in Ullmann type reactions

The functionalized MCM-41-(2-hydroxy-3-propoxypropyl) metformin was prepared and anchored by copper ions to employ as a catalyst for the Ullmann C-X coupling reaction. The catalyst was characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy measurements and, N₂ adsorption–desorption isotherms. The benefits of this catalyst are the use of inexpensive and non-toxic metformin ligand, easy catalyst/product separation, and catalyst recycling. The catalyst can be reused at least for five repeated cycles without a significant loss of its catalytic activity or metal leaching.