10.1021/jacs.9b07323
The research aims to develop a method for the selective formation of C?N bonds, which is crucial for the late-stage functionalization of complex, drug-like small molecules. The study introduces a set of four methods that enable cross-coupling with a broad range of N-nucleophiles, including alkyl and aryl amines, as well as N-containing heterocycles. The process utilizes aryl thianthrenium salts, which can be site-selectively formed by direct C?H functionalization, and are then cross-coupled with N-nucleophiles. Key chemicals involved in the process include aryl thianthrenium salts, various N-nucleophiles, and catalysts such as palladium and copper. The study concludes that these methods provide a new opportunity to achieve molecular diversity via selective late-stage C?N bond formation, setting this amination procedure apart from all previously disclosed arene amination reactions.
10.1002/adsc.200900490
This research study on the N-alkylation of sulfonamides using benzylic alcohols, catalyzed by copper catalysts, through a hydrogen borrowing methodology. The purpose of the study was to develop an efficient and economic method for the synthesis of N-alkylated sulfonamides, which are important building blocks in pharmaceuticals and agrochemicals. The researchers used copper acetate (Cu(OAc)2) and potassium carbonate (K2CO3) as catalysts to achieve excellent yields of secondary amines from the reaction of sulfonamides and alcohols.
10.1021/ja108106h
This research delves into the mechanistic intricacies of an enantioselective palladium-catalyzed alkene difunctionalization reaction. The study's purpose is to enhance the understanding of this reaction mechanism, which is crucial for the rapid increase of molecular complexity and the creation of new chiral centers. The findings revealed that the reaction rate is first-order dependent on palladium concentration, indicating a single palladium atom's involvement in catalysis. The reaction also showed saturation in substrate and copper concentrations, suggesting distinct steps for these components. A linear free energy relationship was observed, correlating substrate electronics to the reaction rate, supporting the hypothesis of a turnover-limiting quinone methide attack. The role of copper was found to be more complex than just catalyst turnover, with evidence suggesting its involvement in quinone methide formation.
10.1016/j.tet.2006.12.082
The research focuses on the molecular engineering of organic dyes containing the N-aryl carbazole moiety for application in solar cells, specifically dye-sensitized solar cells (DSSCs). The purpose of this study was to design and synthesize novel organic dyes that could overcome the limitations of low conversion efficiency and operational stability often associated with organic dyes in DSSCs, as compared to metal-based complexes. The researchers aimed to develop alternative, highly efficient organic dyes that could potentially rival the performance of ruthenium complexes, which are known for their high efficiency but are prohibitively expensive. In the process, various chemicals were used, including 2-iodo-9,9-dimethylfluorene, 3-iodocarbazole, 1-bromo-4-(2,2-diphenylvinyl)benzene, and (2-thienylmethyl)triphenylphosphonium bromide, which were synthesized using modified procedures from previous references. Other chemicals involved in the synthesis steps included tributyl(thiophen-2-yl)stannane, Pd(PPh3)4, copper bronze, potassium carbonate, 18-crown-6, n-butyl lithium, cyanoacetic acid, piperidine, rhodanine-3-acetic acid, and ammonium acetate, among others. These chemicals were utilized in a series of reactions such as coupling, lithiation, and condensation to synthesize the target dyes, which were then tested for their photovoltaic performance in DSSCs.
10.1080/00397919108019768
The research details the synthesis of diphenylic compounds related to the alkaloid taspine, an alkaloid with an unusual diphenylic skeleton that had not been previously synthesized. The study aimed to address the challenges in taspine synthesis, such as asymmetric diphenylic coupling and steric hindrance, by synthesizing simplified models. The researchers reported the synthesis of compound 2, which carries a methyl group instead of the 2-(N-dimethylamino)-ethyl group present in taspine, and the symmetric lactone 32, obtained as a by-product. Key chemicals used in the process included 2-bromo-4-methoxy-3-methoxycarbonyloxy-6-methylbenzaldehyde (S3), 3-benzyloxy-2-bromo-4-methoxybenzaldehyde (6), and various other derivatives and reagents such as copper bronze for the Ullmann reaction, Jones' reagent for oxidation, and hydrogenolysis for the removal of benzyl groups. The final products, dilactones 2 and 3, were obtained in high yields and were found to be insoluble in most solvents, with properties differing from those previously reported for similar structures.
10.10.1002/ejic.201000061
The study investigates a series of mononuclear copper(I) complexes with bis(imino)acenaphthene (BIAN) ligands and various phosphane derivatives. These complexes feature pseudo-tetrahedral geometry and exhibit low-lying metal-to-ligand charge transfer (MLCT) transitions in their electronic spectra, which can be systematically modified by altering substituents on the diimine acceptor subunit and by varying the electron-donating properties and bite angles of the phosphane moiety. The copper(I) complexes are prepared using [Cu(NCCH3)4]PF6 as a low-valent copper precursor, combined with different phosphane ligands and 1,2-bis(arylimino)acenaphthene derivatives. The BIAN ligands serve as redox-active acceptor subunits, while the phosphane ligands act as electron-donating groups. The electronic properties of these complexes, including their optical spectra, excited state energies, solvatochromic behavior, and charge transfer character, are analyzed and correlated with structural variations. The study aims to develop novel multi-electron transfer photosensitizers based on copper, which is an abundant and environmentally benign transition metal, with potential applications in solar cells and photocatalysis.
F,
N,
Xi,
Xn
F:Flammable;
