نتایج جستجو برای: electron withdrawing
تعداد نتایج: 310077 فیلتر نتایج به سال:
Experimental results are reported showing that the photocatalytic oxidation of aromatic compounds containing an electron-donor group (EDG) gives rise mainly to ortho- and para-monohydroxy derivatives while in the presence of an electron-withdrawing group (EWG) all the monohydroxy derivatives are obtained.
Reported here is a palladium catalyzed intramolecular acylcyanation of alkenes using α-iminonitriles. Through this method, highly functionalized indanones are synthesized in moderate to high yields using Pd(PPh3)4, without need for any additional ligands, and a common Lewis acid (ZnCl2). Additionally, the reaction tolerates substitution at various positions on the aromatic ring including electr...
The Pt colloid supported on carbon is an active and selective catalyst for the partial hydrogenation of nitroaromatics with electron-withdrawing substituents to the corresponding N-arylhydroxylamine, indicating an additive-free green catalytic approach for arylhydroxylamine synthesis.
The activation of Ar-Si bonds in aryltrimethylsilane was investigated using a catalytic amount of t-Bu-P4 base and selective functionalizations of aryltrimethylsilanes in the absence of strong electron withdrawing groups on the aromatic rings were accomplished.
We studied the photobleaching of a library of boron dipyrromethene (BODIPY) derivatives with a range of electron densities, and found that the photobleaching rate is influenced by the electron-withdrawing capacity of the substituents. Electron-deficient BODIPYs generated less singlet oxygen, were less reactive to singlet oxygen, and were highly resistant to photobleaching. We confirmed the util...
The synthesis of the azoxybenzenes by the reduction of nitroarenes with reducing agent potassium borohydride in water was reported for the first time. PEG-400 was used as a phase transfer catalyst and could effectively catalyze the reduction. The electronic effects of substituent groups play an important role in determining the reduction efficiencies. Electron-withdrawing substituents promote t...
Using bakers' yeast as a biocatalyst, the chemoselective reduction of aromatic nitro compounds bearing electron-withdrawing groups gave the corresponding hydroxylamines with good to excellent conversion under mild conditions.
Abstract Mechanoluminescence (ML) is the emission of light caused by mechanical stresses on solid, usually crystalline substances. Recently, it has been observed that a specific class organic crystals, N‐alkyl carbazoles, have both low melting points and high proclivity for self‐assembly, making them easily renewable long‐term device applications. To develop new carbazole‐based ML materials app...
Utilizing the symmetry-breaking and π-bridge-extending strategy, three non-fullerene acceptors with DA′D core unit electron-withdrawing are designed synthesized via changing alkoxy-substituted thiophene bridge unit.
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