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。
Complex Polyheterocycles and the Stereochemical Reassignment of Pileamartine A via Aza-Heck Triggered Aryl C–H Functionalization Cascades
作者:Benjamin T. Jones、Javier García-Cárceles、Lewis Caiger、Ian R. Hazelden、Richard J. Lewis、Thomas Langer、John F. Bower
DOI:10.1021/jacs.1c08615
日期:2021.9.29
N-polyheterocycles can be accessed via intramolecular Pd(0)-catalyzed alkene 1,2-aminoarylation reactions. The method uses N-(pentafluorobenzoyloxy)carbamates as the initiating motif, and this allows aza-Heck-type alkene amino-palladation in advance of C–H palladation of the aromatic component. The chemistry is showcased in the first total synthesis of the complex alkaloid (+)-pileamartine A, which has resulted in
displaced upon coordination to rhodiumcomplexes. The efficacy of the resulting Rh-complex coordinated by β-CD-based phosphanes was assessed in Rh-catalyzed hydroformylation of higherolefins. The catalytic system proved to be far more successful and efficient than a system consisting of supramolecularly interacting phosphanes and CDs. The catalytic activity was up to 30-fold higher while the chemo- and regioselectivities
centers provides photo-responsive host–guest properties based on its molecular recognition ability. Here, we construct a self-assembled photoactive Ir(iii) cage-shaped complex that contains anion binding pockets on its rim. The anion recognition ability of the complex enables efficient catalysis of the visible-light-induced E–Z isomerization of an anionic styrene derivative.
具有光敏中心的分子宿主基于其分子识别能力提供光响应主客体特性。在这里,我们构建了一个自组装的光活性 Ir( iii ) 笼形复合物,其边缘包含阴离子结合口袋。该复合物的阴离子识别能力能够有效催化阴离子苯乙烯衍生物的可见光诱导的E - Z异构化。
Dependence of the Chemical Properties of Macrocyclic [Ni<sup>II</sup><sub>2</sub>L(μ-O<sub>2</sub>CR)]<sup>+</sup>Complexes on the Basicity of the Carboxylato Coligands (L<sup>2−</sup>= macrocyclic N<sub>6</sub>S<sub>2</sub>ligand)
作者:Ulrike Lehmann、Julia Klingele、Vasile Lozan、Gunther Steinfeld、Marco H. Klingele、Steffen Käss、Axel Rodenstein、Berthold Kersting
DOI:10.1021/ic101574a
日期:2010.12.6
carboxylates. The resulting carboxylato complexes, isolated as ClO4− or BPh4− salts, have been fully characterized by elemental analyses, IR, UV/vis spectroscopy, and X-ray crystallography. The possibility of accessing the [NiII2L(μ-O2CR)]+ complexes by carboxylate exchangereactions has also been examined. The main findings are as follows: (i) Substitution reactions between 1 and NaO2CR are not affected