Novel Oxidative Ugi Reaction for the Synthesis of Highly Active, Visible-Light, Imide-Acridinium Organophotocatalysts
作者:Andrea Gini、Mustafa Uygur、Thomas Rigotti、José Alemán、Olga García Mancheño
DOI:10.1002/chem.201802830
日期:2018.8.27
A newly designed class of acridinium‐based organophotocatalysts bearing an imide group at the C9‐position is presented. To achieve these unprecedented structures, a synthetic strategy based on a novel straightforward oxidative Ugi‐type reaction at the benzylic position of C9‐unsubstituted acridanes was developed. The introduction of the imide‐unit affords a notable photocatalytic activity enhancement
SN2 Substitution Reactions at the Amide Nitrogen in the Anomeric Mutagens, N-Acyloxy-N-alkoxyamides
作者:Katie L. Cavanagh、Stephen A. Glover、Helen L. Price、Rhiannon R. Schumacher
DOI:10.1071/ch09166
日期:——
amide character and resemble α-haloketones in reactivity. They are susceptible to SN2reactions at nitrogen, a process that is responsible for their mutagenic behaviour. Kinetic studies have been carried out with the nucleophile N-methylaniline that show that, like SN2reactions at carbon centres, the rate constant for SN2 displacement of carboxylate is lowered by branching β to the nitrogen centre, or
N-酰氧基-N-烷氧基酰胺1a是不寻常的异头异构酰胺,其由于双氧基取代而在氮上呈锥体状。通过这种构型,它们失去了大部分酰胺特性,并且在反应性上类似于α-卤代酮。它们在氮气下易受S N 2反应的影响,这是导致其诱变行为的原因。动力学研究已经进行了与亲核试剂Ñ甲基苯胺,显示的是,最喜欢S ñ在碳中心,速率常数为S 2个的反应Ñ通过将β分支到氮中心或烷氧基侧链上的大体积基团,可降低2羧酸盐的置换。然而,羧酸酯离去基团上的支链或大体积基团不影响取代率,其主要由离去的羧酸酯基团的p K A控制。这些结果与氨与N-乙酰氧基-N-甲氧基乙酰胺的模型反应的计算性质相符,但与空间效应对其致突变性的作用相反。
Palladium-Catalyzed Cross-Coupling Reactions of Carboxylic Anhydrides with Organozinc Reagents
作者:Donghui Wang、Zhaoguo Zhang
DOI:10.1021/ol035801w
日期:2003.11.1
[reaction: see text] Negishi-type cross-coupling reaction was effected by employing organozincs and anhydrides or mixedanhydrides that formed in situ fromsodiumsalts of the corresponding acids and ethyl chloroformate under the catalysis of palladium(0). A general method for preparing symmetrical/unsymmetrical ketones was developed.
The syntheses of 32 complexes of the type (η-C5H5)2Ti(OOCC6H4X)2 are reported together with their mass, 1H NMR, 13C NMR, mid- and far-IR spectra. The data are consistent with a model in which the TiOOC bond strength (weaker than that of TiCp and TiHal) is stabilized by electron-withdrawing substituents X on the phenyl rings. The electronic influence of X also extends into the cyclopentadienyl rings
的类型的32种复合物的合成(η-C 5 H ^ 5)2的Ti(OOCC 6 H ^ 4 X)2与它们的质量,一起报告1 H NMR,13 C NMR,中期和远红外光谱。该数据与通过苯环上的吸电子取代基X稳定了TiOOC键强度(比TiCp和TiHal的强度弱)的模型一致。X的电子影响也延伸到环戊二烯基环中。
Weak Coordinating Carboxylate Directed Rhodium(III)-Catalyzed C–H Activation: Switchable Decarboxylative Heck-Type and [4 + 1] Annulation Reactions with Maleimides
group assisted C–H activation with maleimides leading to novel and switchable decarboxylative Heck-type and [4 + 1] annulation products catalyzed by Rh(III) has been reported. In these reactions, solvents play a vital role in switching the selectivity. An aprotic solvent, THF, leads to the decarboxylative Heck-type product while the protic solvent, TFE, results in the [4 + 1] annulation product. The