Synthesis and characterization of a Zn(II) complex of a pyrazole-based ligand bearing a chiral l-alaninemethylester

Determination of catalase activity in samples treated with [ZnCl2(isopropylamine)2]: a novel zinc complex that slows down the decay in activity of catalase extracts

“…As in the case of other Zn() complexes with N donors and bulky ligands, we propose that most likely the Zn() centre of [ZnCl 2 (isopropylamine) 2 ] adopts a distorted tetrahedral geometry. [19][20][21][22][23] From the results of the present study it is clear that [ZnCl 2 (isopropylamine) 2 ] substantially protects catalase activity in catalase extracts. In contrast, neither ZnCl 2 nor the isopropylamine ligand are able to induce this effect on the activity of catalase extracts.…”

“…It is known that Zn() does not have biological redox activity but, instead, it usually works as an electrophilic cofactor in catalytic mechanisms or stabilizes protein structure. 19,26 The TXRF data reported here show that there is no zinc coordination to catalase after incubation of crystalline catalase with [ZnCl 2 (isopropylamine) 2 ]. Although some sort of reversible association between catalase and [ZnCl 2 (isopropylamine) 2 ] might occur, we have not observed by means of circular dichroism spectroscopy changes in the secondary or tertiary structures of catalase in the presence of [ZnCl 2 (isopropylamine) 2 ] (data not shown).…”

9 Zinc, cadmium and mercury

“…72 The crystal structure for [ZnCl 2 (bdmpame)]ؒCH 2 Cl 2 has revealed that the nitrogen atom of the chiral -alanine methyl ester group is not co-ordinated, thereby giving rise to an eight-membered ring in which the nitrogen atoms of each pyrazole moiety are co-ordinated to the zinc centre. 73 The enthalpies of solution in water have been calculated for -α-methionine (Met) and its zinc complexes, [Zn(Met)Cl 74 There has been a review of the various methods for preparing zinc gluconate in which it was proposed that the best method for industrial purposes would be synthesis via the paired electrolysis of glucose. 75 The synthesis and molecular structure have been reported for the isomeleonitrile compound, [Bu 78 have been prepared, characterised, and studied as photodynamic anti-cancer agents.…”

Extremely efficient hydroboration of ketones and aldehydes by copper carbene catalysis

“…1 Because silyl groups and boryl groups represent orthogonal alcohol protecting groups, further advancement of catalytic hydroboration would add significantly to the synthetic toolkit. Hydroboration of organic CQO groups with benign reagents such as pinacolborane (HBpin) and catecholborane (HBcat) has been catalysed with transition metals (Ti, [2][3][4][5][6] Zn, [7][8][9][10][11] and Ru 12,13 ) and with main group elements (Mg, [14][15][16] P, 17 Ga, 18 Ge, and Sn 19 ). In selected cases, modest to good levels of enantioselectivity were achieved using chiral ligands, 3,4,[6][7][8][9]11,18 although further development of stereoselectivity is needed.…”