Dinuclear zinc(ii) pyrazolates with different degrees of ring-fluorination and their use in zinc(ii) mediated olefin aziridination

Abstract

Zinc complexes [{(3,5-(CF)Pz)ZnEt}(μ-THF)] (1), [{(3-(CF),5-(t-Bu)Pz)ZnEt}(μ-THF)] (2), and [{(3,5-(i-Pr)Pz)ZnEt}(μ-THF)] (3) adopt dinuclear structures with zinc sites bridged by a THF molecule and two pyrazolate ligands. The zinc complex 1 that features the weakest donating pyrazolate is the best catalyst among the three for the aziridination of styrene and cis-cyclooctene with PhI[double bond, length as m-dash]NTs.

Effects on the magnetic interaction caused by molecular recognition in complexes of 1,2-azole-based oxamate and [Cu(bpca)]+ units

“…Focusing on 1H-pyrazole-based ligands, their coordination chemistry is very rich due to the possibility of coordinating to metal atoms in their neutral or deprotonated form since its NH group can be easily deprotonated in the presence of transition metal ions and a base (apparent pK a = 19,8 for 1Hpyrazole in DMSO). The pyrazolate anion acts as a bismonodentate kN:kN′ ligand, forming di-, [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] tri-, [22][23][24][37][38][39][40][41][42][43][44][45][46][47] tetra- 22,[48][49][50][51][52][53][54] and polymetallic synthons [55][56][57][58][59][60] or even coordination polymers. [61][62]…”

“…Focusing on 1 H -pyrazole-based ligands, their coordination chemistry is very rich due to the possibility of coordinating to metal atoms in their neutral or deprotonated form since its NH group can be easily deprotonated in the presence of transition metal ions and a base (apparent p K a = 19,8 for 1 H -pyrazole in DMSO). The pyrazolate anion acts as a bis-monodentate kN:kN′ ligand, forming di-, 22–38 tri-, 22–24,37–47 tetra- 22,48–54 and polymetallic synthons 55–60 or even coordination polymers. 61–64 Relatively strong magnetic interactions between paramagnetic centers such as Cu II , Co II , and Fe II can be mediated through this coordination mode.…”

1,8‐Bis(borylamido)naphthalene Complexes of Lithium and Zinc(II) Including a Zinc(II) Isocyanide Adduct

“…As a part of our ongoing investigations of the chemistry of zinc supported by nitrogen‐based chelators, we became interested in the dianionic, 1,8‐bis(amido)naphthalene systems in order to provide an entry to neutral zinc(II) amide complexes. These ligands provide a highly conjugated ligand backbone and an adjustable steric/electronic profile at the metal site through substituents on the nitrogens.…”