90832-35-2Relevant articles and documents
The visible-light-driven transfer hydrogenation of nicotinamide cofactors with a robust ruthenium complex photocatalyst
Chen, Fushan,Deng, Li,Dong, Wenjin,Tang, Jie,Xian, Mo,Zhao, Lijun
, p. 2279 - 2287 (2020/04/20)
The highly efficient regeneration of nicotinamide cofactors has been successfully achieved with a quantum yield (Φ) of 7.9 × 10-3via photocatalytic transfer hydrogenation in the presence of the ruthenium complex Ru(tpy)(biq)Cl2 (where tpy = 2,2′:6′,2′′-terpyridine and biq = 2,2′-bisquinoline). The photocatalytic system is not only highly efficient but also tolerant to amino acid residues. The combination of this photocatalyst with glutamate dehydrogenase enabled the controllable and efficient synthesis of l-glutamate to be realized. A mechanism involving light-induced ligand exchange, decarboxylation and hydride transfer has been proposed. Kinetic isotope experiments revealed that the decarboxylation of [Ru(tpy)(biq)HCOO]+ to [Ru(tpy)(biq)H]+ was the rate-determining step with a small apparent activation energy of 3.2 ± 0.4 kcal mol-1. The hydricity of [Ru(tpy)(biq)H]+ was estimated, via reaction equilibrium, to be 40 ± 3 kcal mol-1
Effects of Base on Oxidation of an NADH Model Compound by Iron(III) Complexes and Tetracyanoethylene
Fukuzumi, Shunichi,Kondo, Yuji,Tanaka,Toshio
, p. 673 - 680 (2007/10/02)
Effects of base on both an electron-transfer reaction from an NADH model compound, 1-benzyl-1,4-dihydronicotinamide (BNAH) to (3+) (N-N = 2,2'-bipyridine and 1,10-phenanthroline) and a hydride transfer from BNAH to tetracyanoethylene (TCNE) in acetonitrile have been examined.The stoicheiometry of the electron transfer from BNAH to (3+) in the absence of a base indicates that BNAH is a one-electron donor.In the presence of a base, however, BNAH acts as an apparent two-electron donor, when the two-electron transfer proceeds via a multistep process; a fast one-electron transfer from BNAH to (3+) occurred, followed by the rate-determining deprotonation of BNAH+. by base and the subsequent fast electron transfer from BNA. to (3+).The rate constants for the proton transfer from BNAH+. to a series of pyridine derivatives have been determined.In the reduction of TCNE by BNAH, BNAH appears to be a two-electron donor in both the absence and presence of a base.Rates of the reduction of TCNE by BNAH increased with inceasing base concentration, suggesting the involvement of BNAH+. as an intermediate in the hydride transfer from BNAH to TCNE.The kinetic analyses have led to the evaluation of the proton transfer rate constants for the deprotonation of BNAH+. with various bases, which accord with those obtained from the electron-transfer reactions of BNAH with (3+) in the presence of bases.Based on the Broensted plot of the proton transfer rate constants as well as the variation of the primary kinetic isotope effects kH/kD with the pKa of the base, the pKa value for BNAH+. has been evaluated as 3.6 +/-0.4.
