Simple Preparations of C-4-tert-Butylated NADH/NAD+ Analogs
摘要:
The addition of tert-butyl Grignard reagent to the 1-benzyl-3-carbamoylpyridinium salt (1) gives a mixture of the C-4-(2), C-6-(3), and C-2-tert-butylated dihydronicotinamides (4) in which the desired 1,4-isomer predominates. Stable cristalline 1-benzyl-4-tert-butyl-1,4-dihydronicotinamide (2) can be easily isolated. Oxidation of the product with the 1-benzyl-3-cyanoquinolinium ion (6) was found to be strongly solvent-dependent. In acetonitrile, exclusive hydride transfer gives the corresponding C-4-tert-butylated pyridinium ion (5). In methanol, an interesting tert-butyl transfer from 1,4-dihydronicotinamide (2) to quinolinium (6) occurs competitively, and predominates in the presence of a catalytic amount of formic acid; the resulting C-4-tert-butylated 1,4-dihydroquinoline derivative (8) can be readily isolated.
Photoalkylation of 10-Alkylacridinium Ion via a Charge-Shift Type of Photoinduced Electron Transfer Controlled by Solvent Polarity
作者:Shunichi Fukuzumi、Kei Ohkubo、Tomoyoshi Suenobu、Kouta Kato、Mamoru Fujitsuka、Osamu Ito
DOI:10.1021/ja004311l
日期:2001.9.1
(DeAcrH+) in a nonpolar solvent (benzene) is found to be as efficient as those of 10-methylacridinium cation (MeAcrH+) and DeAcrH+ in a polar solvent (acetonitrile). Irradiation of the absorption bands of MeAcrH+ in acetonitrile solution containing tetraalkyltin compounds (R(4)Sn) results in the efficient and selective reduction of MeAcrH+ to yield the 10-methyl-9-alkyl-9,10-dihydroacridine (AcrHR)
activation energies of various hydridetransferreactions was developed according to transition state theory using the Morse-type free energy curves of hydride donors to release a hydride anion and hydrideacceptors to capture a hydride anion and by which the activation energies of 187 typical hydride self-exchange reactions and more than thirty thousand hydride cross transferreactions in acetonitrile were
Mechanism of Electron Transfer Oxidation of 4-Substituted 1-Benzyl-1,4-dihydronicotinamides
作者:Naoki Takada、Shinobu Itoh、Shunichi Fukuzumi
DOI:10.1246/cl.1996.1103
日期:1996.12
Electron transfer oxidation of variously 4-substituted 1-benzyl-1,4-dihydronicotinamides (RBNAH) by [Fe(phen)3]3+ (phen = 1,10-phenanthroline) results in formation of RBNAH•+, followed by cleavage of the C(4)-H or C(4)-C bond of RBNAH•+ depending on the substituent R. In particular, the C(4)-C bond cleavage of t-BuBNAH•+ yields exclusively BNA+ and tert-butylradical (t-Bu•) which is detected by applying a rapid mixing flow electron spin resonance (ESR) technique.
Thermodynamic Control in Ion Radical Cleavages through Out-of-Cage Diffusion of Products. Dynamics of C−C Fragmentation in Cation Radicals of <i>tert</i>-Butylated NADH Analogues and Other Ion Radicals
alkyl group, cationradicals of NADHanalogues alkylated para to the nitrogen atom (AHR), generated by direct or indirect electrochemical means, may undergo C−C fragmentation or deprotonation. The former reaction is dominant with the tert-butyl substituent and the latter with methyl and phenyl substituents. It is shown that the cleavage reaction produces AH+ and the tert-butyl radical which is then
Reduction and alkylation of (η6-arene)tricarbonylmanganese complexes using alkyl-substituted coenzyme NADH models
作者:Lidong Cao、Li Zheng、Qiliang Huang
DOI:10.1016/j.jorganchem.2014.06.021
日期:2014.10
direct tert-butyl group transfer was observed between t-BuBNAH and (η6-arene)Mn(CO)3+ complexes in reflux acetonitrile without a radical initiator, and the corresponding tert-butylradical addition products were achieved. The substituents on the aromatic ring significantly influence the reactivity and chemoselectivity. The electron-withdrawing group helps to promote the reactions. The radical inhibition