5,5″-Disubstituted 2,2′:6′,2″-Terpyridines through and for Metal-Mediated Cross-Coupling Chemistry
摘要:
The 0.3-5 g scale syntheses of the 2,2':6',2 "-terpyridines 3, 6, 9, and 10 are described. The pyridine units are connected to one another by Pd-catalyzed cross-coupling reactions. This method allows the easy introduction of halogen, stannyl, and boronic ester functionalities at positions C-5 and C-5 "; this results in a novel functionality pattern for terpyridines that considerably widens the applicability of this class of tridentate ligands for supra- and macromolecular applications. The feasibility of growth reactions with these novel terpyridines was demonstrated by the synthesis of compounds 12a-c.
Simple Ligand Modifications with Pendent OH Groups Dramatically Impact the Activity and Selectivity of Ruthenium Catalysts for Transfer Hydrogenation: The Importance of Alkali Metals
作者:Cameron M. Moore、Byongjoo Bark、Nathaniel K. Szymczak
DOI:10.1021/acscatal.6b00229
日期:2016.3.4
Remarkable differences in selectivity and activity for ruthenium-catalyzed transfer hydrogenation are described that are imparted by pendent OH groups. Kinetic experiments, as well as the study of control complexes devoid of OH groups, reveal that the pendent OH groups serve to orient the ketone substrate through ion pairing with an alkalimetal under basic conditions. The deprotonation of the OH groups
Selective synthesis of mono- and distannylpyridines from chloropyridinols via an SRN1 mechanism
作者:Gustavo F. Silbestri、Marcos J. Lo Fiego、María T. Lockhart、Alicia B. Chopa
DOI:10.1016/j.jorganchem.2010.08.032
日期:2010.11
selective two-stepsynthesis of either mono- or distannylated pyridines from commercially available pyridinols, involving its conversion to the corresponding diethyl pyridyl phosphates (pyDEP) followed by the reaction with Me3SnNa in liquid ammonia, is described. The results obtained clearly indicate that the reactions proceed through an unimolecular radical nucleophilic substitution mechanism (SRN1) with
Simple and Mild Method for Preparation of .ALPHA.-Pyridinecarboxylates and .ALPHA.-Pyridyl Ketones via Trimethylstannyl Derivatives.
作者:Yutaka YAMAMOTO、Hidekazu OUCHI、Takuo TANAKA
DOI:10.1248/cpb.43.1028
日期:——
Alkoxycarbonylation and acylation at the α-position of pyridine, quinoline, and isoquinoline via the respective trimethylstannyl derivatives were satisfactorily performed by employing ethyl chloroglyoxylate and acylformyl chloride under mild conditions.
Facile hydrogen atom transfer to iron(<scp>iii</scp>) imido radical complexes supported by a dianionic pentadentate ligand
作者:Denis M. Spasyuk、Stephanie H. Carpenter、Christos E. Kefalidis、Warren E. Piers、Michael L. Neidig、Laurent Maron
DOI:10.1039/c6sc01433j
日期:——
tetrapodal pentadentate diborate ligand is introduced. This ligand forms a high spin neutral iron(II) complex that reacts with a variety of organoazides to yield transient Fe(III) imido radicals that are extremely potent hydrogen atom abstractors. The nature of these species is supported by full characterization of the Fe(III) amido products, kinetic studies, density functional computations and Mössbauer spectroscopy
引入了双阴离子四足五齿二硼酸酯配体。该配体形成高自旋中性铁(II)配合物,该配合物与多种有机叠氮化物反应,生成瞬态Fe(III)酰亚胺基团,这些自由基是非常有效的氢原子抽象剂。这些物种的性质得到了Fe(III)酰胺基产物的全面表征,动力学研究,密度泛函计算和–C 6 H 4 - p - t Bu取代衍生物的Mössbauer光谱学的支持。
Synthesis of Benzene- and Pyridinediboronic Acids via Organotin Compounds
作者:Sandra D. Mandolesi、Santiago E. Vaillard、Julio C. Podestá、Roberto A. Rossi
DOI:10.1021/om020163r
日期:2002.10.1
s react with borane in THF to give intermediates which on hydrolysis lead to benzene- and pyridinediboronic acids in 79−83% yield. While oxidation of the benzenediboronicacids with alkaline hydrogen peroxide gives the corresponding 1,3- and 1,4-dihydroxybenzenes, the pyridinediboronic acids lead via a double Suzuki reaction with 4-iodoanisole to 2,5- and 2,6-bis(4-methoxyphenyl)pyridines and react