Tetranuclear Zn₂Ln₂ coordination clusters as catalysts in the Petasis borono-Mannich multicomponent reaction

Abstract

We report for the first time the efficiency of heteronuclear Zn/Ln coordination clusters (CCs) as catalysts for the multicomponent Mannich-type condensation that involves amines, aldehydes and boronic acids, known as the Petasis borono-Mannich (RBR) reaction.

A tetranuclear CuII2DyIII2 coordination cluster as a Suzuki (C–C) coupling reaction promoter

“…3 In this direction, 3d/4f in situ [4][5][6] or well characterised coordination clusters have recently emerged as sustainable catalytic platforms with advantages in their ease synthesis, good abundance (in spite of belonging to the so-called rare earths) and low cost. 7 Our group has established the efficacy of a series of tetranuclear [M II 2Ln III 2L4(X)2(solv)2] (M = Ni, Co, Cu, Zn, X = Cl, NO3, Ln = Y, Dy, Gd) for domino-electro cyclization and Lewis acid reactions, [8][9][10][11] whereas other groups have, successfully, used them in redox, [12][13][14] co-polymerization 15 and carbon dioxide fixation reactions. 16,17 The metal-promoted Suzuki-Miyaura coupling includes organoboron derivatives and carbon electrophiles, and represents a valuable procedure for a C-C bond formation (Scheme 1).…”

Tuning Nuclearity of Dysprosium (III) Complexes by Controlling Substitution on Ligand Molecule

“…Coordination chemistry of lanthanide ions has been increasingly exploited research area because of its interesting magnetic, [1][2][3][4] luminescent [5][6][7][8][9][10][11][12][13][14] , catalytic applications. [15][16][17][18][19] Various multinuclear lanthanide clusters with remarkable structures, including Ln 48 , [20] Ln 60 , [21,22] Ln 72 , [23] , Ln 104 , [24] have been synthesized. Dysprosium complexes [25][26][27][28] have received great deal of importance in recent times due to significant breakthrough in hysteresis temperature, inversion energy barrier that has given hope for practical single-molecule magnets (SMMs).…”

Dinucleating Schiff base ligand in Zn/4f coordination chemistry: synthetic challenges and catalytic activity evaluation

“…The second group of 3d/4f CCs includes paradigms of wellcharacterised pre-catalyst or postulated active species. [24][25][26][27][28][29][30][31][32][33] The advantage of the isolation and use of well-defined species compared to the former set is the possibility to extract mechanistic information by performing controlled experiments and thus shed light in the catalytic nature of the 3d/4f PCCs. Moreover, this approach allows to fine tune the reaction conditions (i.e.…”

“…33 Our group has reported the synthesis and characterization of a series of isoskeletal "butterfly" shaped tetranuclear [3d II 24f III 2L4] 2+ (3d = Ni, Co, Cu, Zn, 4f = Y, Sm, Dy, Gd, Sm) CCs, in which the coordination spheres of the 3d and the 4f ions are not fully saturated, and their use in a series of organic transformations. [26][27][28][29]32 This catalytic library showcased cooperative catalytic behaviour, while variation of the 4f centre permitted the extraction of useful mechanistic information. 29 However, our efforts to obtain isoskeletal derivatives altering the counter ion and/or the lanthanide source yielded in the isolation of unexpected products with variant formulations, which could be attributed to several parameters including the pH of the reaction and the coordination ability of the anion and/or the ionic radii of the lanthanide element.…”