Discipline of Chemistry, School of Basic Sciences, Indian Institute of Technology Indore, Simrol, Khandwa Road, Indore 453552, India.
Dalton Trans. 2021 Apr 14;50(14):4848-4858. doi: 10.1039/d1dt00108f. Epub 2021 Mar 19.
Designing metal complexes as functional models for metalloenzymes remains one of the main targets in synthetic bioinorganic chemistry. Furthermore, the utilization of the product(s) derived from the catalytic reaction for subsequent organic transformation that occurs in biological systems is an even more difficult challenge for biochemists. Urease, the most efficient enzyme known, catalyzes the hydrolysis of urea and it contains an essential dinuclear Ni cluster in the active site. Inspired by the catalytic properties of urease, two dinickel(ii) complexes viz. NiL(OAc)(HO) (1) and NiL(OAc)(HO) (2) [HL1 = 2,4-dimethyl-6-{[(2'-dimethyl aminoethyl)methylamino]methyl}-phenol and HL2 = 2,4-dichloro-6-{[(2'-dimethyl aminoethyl)methylamino]methyl}-phenol] have been synthesized and characterized in this report. Both the complexes have shown the urease kind of activity with the liberation of ammonia from urea in aqueous solution. The plausible mechanistic pathway and kinetics of the reactions have been studied. Besides, the liberated ammonia has been utilized in the one-pot synthesis of biologically active products like 2-amino-3-cyanopyridines and their derivatives in aqueous medium with excellent yields.
设计金属配合物作为金属酶的功能模型仍然是合成生物无机化学的主要目标之一。此外，利用催化反应产物进行随后在生物系统中发生的有机转化，对于生物化学家来说是一个更加困难的挑战。脲酶是已知最有效的酶，它催化尿素的水解，其活性部位含有一个必需的双核 Ni 簇。受脲酶催化特性的启发，我们合成并表征了两种双核 Ni(ii)配合物，即 NiL(OAc)(HO)（1）和 NiL(OAc)(HO)（2）[HL1 = 2,4-二甲基-6-｛[(2'-二甲基氨基乙基)甲基氨基]甲基｝-苯酚和 HL2 = 2,4-二氯-6-｛[(2'-二甲基氨基乙基)甲基氨基]甲基｝-苯酚]。这两种配合物都在水溶液中显示出脲酶样的活性，从尿素中释放出氨。研究了反应的可能的机理途径和动力学。此外，在水相介质中，通过一锅法合成了具有生物活性的产物，如 2-氨基-3-氰基吡啶及其衍生物，产率很高，利用了释放的氨。
