对于可见光诱导的不对称合成的巨大发展,对光化学反应的手性催化剂有很高的要求。现在,已经报道了基于地球上丰富的金属和手性N4配体的手性八面体络合物。一种定义明确的手性CoII配合物被证明是在可见光诱导的烷基和酰基基团烯酮的共轭加成中的有效催化剂,提供了合成有价值的手性酮和1,4-二羰基化合物,产率为47-> 99%高达97:3 er
Introduction of alkyl groups on azodicarboxylate esters is an important method to prepare alkyl aminederivatives. Herein, we report reactions of 4-alkyl-1,4-dihydropyridines as alkylation reagents with di-tert-butyl azodicarboxylate to prepare alkyl aminederivatives under heating conditions. The alkylation reactions via C–C bond cleavage of the dihydropyridines are achieved in the absence of catalysts
Hydrogenation was only the beginning: Hantzsch esters have now been used to transferalkyl groups to imines under mild catalytic conditions to provide a variety of amines (see scheme). Benzyl, secondary alkyl, and tertiary alkyl groups containing ether, ester, and hydroxy functionalities were transferred successfully. The use of Hantzsch esters as alkylation reagents offers a practical and complementary
Building Congested Ketone: Substituted Hantzsch Ester and Nitrile as Alkylation Reagents in Photoredox Catalysis
作者:Wenxin Chen、Zheng Liu、Jiaqi Tian、Jin Li、Jing Ma、Xu Cheng、Guigen Li
DOI:10.1021/jacs.6b06379
日期:2016.9.28
For the first time, 4-alkyl Hantzsch esters were used to construct molecules with all-carbon quaternary centers by visible light-induced photoredox catalysis via transfer alkylation. Up to a 1500 h(-1) turnover frequency was achieved in this reaction. Reactions of 4-alkyl Hantzsch nitriles as tertiary radical donors joined two contiguous all-carbon quaternary centers intermolecularly, and this chemistry
Oxidation of 4-aryl- and 4-alkyl-substituted 2,6-dimethyl-3,5-bis(alkoxycarbonyl)-1,4-dihydropyridines by human liver microsomes and immunochemical evidence for the involvement of a form of cytochrome P-450
作者:Ronald H. Boecker、F. Peter Guengerich
DOI:10.1021/jm00159a007
日期:1986.9
lost; these compounds also inactivated cytochromeP-450 and caused the loss of nifedipine oxidase activity after enzymaticoxidation. All of these reactions were extensively inhibited by an antibody raised to purified human liver nifedipine oxidase cytochromeP-450 (P-450NF), indicating a major role for this enzyme in the oxidation of these compounds. Oxidation of the 4-alkyl compounds led not only
An efficient, metal-free, room temperature aromatization of Hantzsch-1,4-dihydropyridines with urea–hydrogen peroxide adduct, catalyzed by molecular iodine
A mild, highly efficient and metal-free synthetic method for aromatization of 1,4-dihydropyridines employing urea–hydrogen peroxide adduct as oxidant catalyzed by 20 mol % of molecular iodine was developed. The reaction was carried out in ethyl acetate at roomtemperature and the products were isolated in high to excellent yields. A plausible free-radical mechanism is proposed based on results obtained