Refernces
10.1016/j.molstruc.2010.01.059
The research focuses on the 1,3-dipolar cycloaddition reaction of N-[4-nitrophenyl]-C-[2-furyl] nitrilimine with electron-rich dipolarophiles such as vinyl acetate, 2-propyne-1-ol, and styrene, aiming to synthesize specific pyrazole derivatives. The reaction's reactivity and regiochemistry were experimentally investigated and supported by theoretical DFT-based reactivity indexes using the B3LYP/6-31G(d) level of theory. The study employed a variety of analytical techniques including 1H and 13C NMR, IR spectroscopy, mass spectrometry, and elemental analysis to characterize the synthesized products. The regioselectivity of the reactions was further analyzed using DFT-based reactivity indexes, such as Fukui indexes, local softnesses, and local electrophilicity, to predict the favored interaction sites and elucidate the reaction mechanisms. The research successfully predicted the regiochemistry of the isolated cycloadducts and provided insights into the factors influencing the regioselectivity of these reactions.
10.1002/ejoc.200400471
The study focuses on the synthesis and reactions of 7-(dimethylamino)tricyclo[5.2.2.01,6]undec-10-en-9-ones, which are derived from β-cyclohexenyl β-dimethylamino-substituted α,β-unsaturated Fischer carbenes. The main chemicals used include pentacarbonyl[(2E)-3-cyclohexenyl-3-(dimethylamino)-1-ethoxy-2-propen-1-ylidene]chromium (1-Cr) and -tungsten (1-W) complexes, various alkynes (2), and styrenes (8). These chemicals serve the purpose of undergoing a series of reactions such as 6π-electrocyclization and reductive elimination to yield cyclohexane-annelated cyclopentadiene (6), which further reacts with alkynes and styrenes in Diels-Alder reactions to form highly functionalized tricycles with high regio- and diastereoselectivity. The study also investigates the influence of substituents on the alkynes and the nature of the transition metal in the carbene complexes on the reaction outcomes. The synthesized compounds exhibit interesting properties such as dual fluorescence and large radiative rate constants, which could have potential applications in areas like light-emitting diodes (LEDs).
10.1055/s-2003-36803
The research focuses on the synthesis and characterization of chiral calix[4]arene analogs, which are locked in the cone conformation through photocycloaddition. The purpose of this study was to develop a simple synthetic route to chiral calixarene analogs using styrene derivatives and to investigate their complexation with alkali metal ions and their extractability from aqueous to organic phases. The researchers used bisphenol derivatives as starting materials and performed a series of chemical reactions involving monoetherification, etherification, and vinylation with reagents such as Li2CO3, CH3I, K2CO3, and PdCl2(PPh3)2. The key conclusion of the study is that the synthesized calix[4]arene analogs formed 1:1 complexes with alkali metal ions and exhibited a preference for extracting larger metal picrates over smaller ones. The chiral calixarene analogs were successfully resolved using HPLC, and the study demonstrated that the calix[4]arene geometry could be sophisticatedly modified to dramatically change ion selectivity and extractability.
10.1016/j.jorganchem.2010.09.064
The study presents a rhenium-catalyzed method for synthesizing 2-alkenylbenzylamines from aromatic aldimines and alkenes. The process involves the activation of an aromatic C(sp2)-H bond, followed by the insertion of an alkene into this bond, beta-hydride elimination, and finally the hydrogenation of the imino group of the aromatic aldimine. The research demonstrates that using the rhenium-hydride complex catalyst [HRe(CO)4]n leads to high yields of 2-alkenylbenzylamines, contrasting with other rhenium catalysts which may lead to different products like quinolines via an aza-Diels-Alder reaction. The study also explores the scope of the reaction with various aldimines and alkenes, providing insights into the reaction mechanism and the factors influencing the product selectivity and yield.
10.1021/ol102398y
The study presents an innovative iterative synthesis method for heterotelechelic oligo(phenylene-vinylene)s (OPVs) utilizing olefin cross-metathesis. This approach allows for the creation of oligomers with controlled lengths and paves the way for their assembly into repeating sequence copolymers (RSCs). The process is initiated by a cross-metathesis reaction between olefin-terminated oligomers and a vinylbenzaldehyde, yielding aldehyde-end-capped OPVs. These can then be transformed into metathesis-ready vinyl groups or used for further functionalization, such as the formation of donor-acceptor complexes. The study demonstrates the synthesis of various OPVs with different conjugation lengths, which exhibit tunable optical properties, and also explores the potential for creating complex copolymers through the conversion of OPVs into RSCs. The method's versatility is highlighted by the successful functionalization of OPVs and the potential for applying this metathesis-based coupling to phenylene monomers with a variety of substituents.
10.1039/c5nj02378e
The study presents a novel one-pot method for the catalytic cyclopropanation of various alkenes with unsubstituted hydrazones. The process utilizes iodosobenzene as an oxidant to convert hydrazones into diazo compounds, which are then cyclopropanated in the presence of a nickel(II) catalyst, Ni(OH)2. This method allows for the efficient generation of cyclopropane products under mild conditions (80°C) within a short time frame (5 minutes to 4 hours) and with moderate to good yields (42–91%). The protocol is applicable to a wide range of substrates, including aryl alkenes with different electronic effects, aliphatic alkenes with halogen functional groups, and alkyl acrylates. The study also explores the reaction mechanism and provides a promising approach to synthesizing cyclopropane compounds, which are prevalent in natural products and have significant value in pharmaceutical chemistry.
10.1021/ol0523143
The study investigates a method for synthesizing 1,1-diarylalkanes and 1-aryl-1-heteroarylalkanes using FeCl3 as a catalyst. The researchers explored the hydroarylation of styrenes with electron-rich arenes and heteroarenes, finding that FeCl3 effectively catalyzes the reaction under mild conditions, yielding high selectivity and good yields. The study involved various styrenes (such as 4-chlorostyrene and simple styrene) and electron-rich arenes (including o-xylene and methylthiophenes), with FeCl3 playing a crucial role in facilitating the addition of these olefins to the aromatic compounds. The reactions were optimized for temperature, solvent, and reaction time, with the best results achieved at 80 °C using the arene as solvent. The developed method offers a practical and cost-effective approach to synthesizing diarylalkanes, which are important in the pharmaceutical and chemical industries.
Xn,
T,
F
Xn:Harmful;
