2-Amino-4-aryl-4H-pyran derivatives could be prepared rapidly and smoothly in good to excellent yields by the microwave-assisted liquid-phase strategy of multicomponent synthesis on polyethylene ...glycol.
The concatenation of Suzuki coupling and two‐fold Buchwald‐Hartwig amination in sequentially palladium‐catalyzed consecutive multicomponent syntheses paves a concise, convergent route to diversely ...functionalized para‐biaryl‐substituted triarylamines (p‐bTAAs) from simple, readily available starting materials. An extensive library of p‐bTAAs permits comprehensive investigations of their electronic properties by absorption and emission spectroscopy, cyclic voltammetry, and quantum chemical calculations, which contribute to a deep understanding of their electronic structure. The synthesized p‐bTAAs exhibit tunable fluorescence from blue to yellow upon photonic excitation with quantum yields up to 98 % in solution and 92 % in the solid state. Furthermore, a pronounced bathochromic shift of the emission maxima by increasing solvent polarity indicates positive emission solvatochromism. Aggregation‐induced enhanced emission (AIEE) in dimethyl sulfoxide (DMSO)/water mixtures causes the formation of intensely blue fluorescent aggregates. Cyclic voltammetry shows reversible first and second oxidations of p‐bTAAs at low potentials, which are tunable by variation of the introduced para substituents. 3D Hammett plots resulting from the correlation of oxidation potentials and emission maxima with electronic substituent parameters emphasize the rational design of tailored p‐bTAAs with predictable electrochemical and photophysical properties.
A single palladium catalyst catches two birds with one stone by multicomponent Suzuki and Buchwald‐Hartwig coupling to give a library of redox‐active triarylamine (TAA) luminophores. Redox potentials, absorption and emission energies together with (TD)DFT calculations of the electronic structure set the stage for structure‐property relationships for a rational design of tunable TAAs.
Thiazoles are important sulfur-containing molecules that are widely used in diverse fields such as pharmaceuticals, agrochemicals, and material sciences. This is the first report on the ...PEG-300-mediated one-pot synthesis of 2-(2-hydrazinyl) thiazole derivatives from ketones, thiosemicarbazide, and α-halo ketones. Here PEG-300 acts as a solvent as well as supporting catalyst. Formation of compounds was confirmed by IR,
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H NMR,
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C NMR, and mass spectroscopic studies.
A series of 2-(2-hydrazinyl) Thiazole derivatives have been synthesized from substituted ketones, thiosemicarbazide & α-halo ketones using PEG-300 as a reaction medium via one-pot approach.
