Water-soluble phenanthroline complexes of rhodium, iridium and ruthenium for the regeneration of NADH in the enzymatic reduction of ketones
Water-soluble phenanthroline complexes of rhodium, iridium and ruthenium for the regeneration of NADH in the enzymatic reduction of ketones
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DOI：
10.1002/ejic.200700505
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发表时间：
2007-10-01
影响因子：
2.3
通讯作者：
Stepnicka, Petr
中科院分区：
文献类型：
--
作者：
Canivet, Jerome;Suess-Fink, Georg;Stepnicka, Petr
在醇脱氢酶催化的酮的对映选择性还原中消耗的烟酰胺辅酶NADH需要再生以保持酶活性。因此，我们研究了阳离子配合物[（eta（5）-（CMe 5）-Me-5）Rh（NnN）Cl]（+）的催化性能（1：N布尔AND N = 1，10-菲咯啉; 2：NnN = 5-硝基-1，10-菲咯啉; 3：NnN = 5-氨基-1，10-菲咯啉），[（eta（5）-C5Me5）Ir（N boolean AND N）CI]（+）（4：N布尔AND N = 5-硝基-1，10-菲咯啉）和[（eta（6）-C-6，Me-6）Ru（N boolean AND N）Cl]（+）（五：NnN = 5-硝基-1，10-菲咯啉），分离为水溶性氯化物盐，用于NAD（+）在水溶液中的转移氢化以产生NADH。最好的结果得到了铑配合物1，它给出了催化周转频率高达2000小时（-1），在水溶液中，在pH值为7和60 ℃，甲酸钠作为氢源。当这种NADH再生催化系统与NADH依赖性酶结合时，可以以高对映体选择性化学酶促还原前手性酮，例如苯乙酮或4-苯基丁-2-酮。将马肝醇脱氢酶（HLADH）或红球菌属的醇脱氢酶（S-ADH）与1/甲酸作为NADH再生系统的组合导致ee值高达98%，这取决于底物和酶的性质。为了解释不同的催化活性，已经研究了配合物1 - 5的电化学行为。((c)Wiley-VCH Verlag GmbH & Co. KGaA，69451魏因海姆，德国，2007）
The nicotinamide coenzyme NADH, consumed in enantioselective reduction of ketones catalysed by alcohol dehydrogenases, needs to be regenerated in order to maintain enzymatic activity. We therefore studied the catalytic potential of the cationic complexes [(eta(5)-(CMe5)-Me-5)Rh(NnN)Cl](+) (1: N boolean AND N = 1,10-phenanthrohne; 2: NnN = 5 -nitro-1, 10-phenanthroline; 3: NnN = 5-amino-1, 1 0-phenanthroline), [(eta(5)-C5Me5) Ir(N boolean AND N)CI](+) (4: N boolean AND N = 5-nitro-1, 10-phenanthroline) and [(eta(6)-C-6,Me-6)Ru(N boolean AND N)Cl](+) (5: NnN = 5-nitro-1,10-phenanthroline), isolated as the water-soluble chloride salts, for transfer hydrogenation of NAD(+) to give NADH in aqueous solution. The best results were obtained with rhodium complex 1, which gave catalytic turnover frequencies up to 2000 h(-1) in aqueous solution at pH 7 and 60 degrees C with sodium formate as the hydrogen source. When this NADH-regenerating catalytic system is combined with NADH-dependent enzymes, it is possible to chemoenzymatically reduce prochiral ketones such as acetophenone or 4-phenylbutan-2-one with high enantioselectivity. Combination of horse liver alcohol dehydrogenase (HLADH) or alcohol dehydrogenase from Rhodococcus sp. (S-ADH) with 1/formate as the NADH-regenerating system resulted in ee values up to 98 %, depending on the nature of the substrate and the enzyme. In order to explain the different catalytic activities, the electrochemical behaviour of complexes 1-5 has been studied.((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)