One-pot four-component synthesis of pyrimidyl and pyrazolyl substituted azulenes by glyoxylation–decarbonylative alkynylation–cyclocondensation sequences

A novel one-pot four-component synthesis of pyrimidyl- and pyrazolylazulenes through the use of glyoxylation–decarbonylative alkynylation–cyclocondensation sequences starting from azulene or guaiazulene as substrates, gives rise to the formation of the target compounds in moderate to good yields

Consecutive Three-Component Synthesis of 3-(Hetero)Aryl-1H-pyrazoles with Propynal Diethylacetal as a Three-Carbon Building Block

A novel consecutive three-component synthesis of 3-(hetero)aryl-1H-pyrazoles via room temperature Sonogashira arylation of propynal diethylacetal used as a propargyl aldehyde synthetic equivalent has been disclosed. The final acetal cleavage-cyclocondensation with hydrazine hydrochloride at 80 °C rapidly furnishes the title compounds in a one-pot fashion

Highly Convergent Synthesis of Intensively Blue Emissive Furo[2,3-c]isoquinolines by a Palladium-catalyzed Cyclization Cascade of Unsaturated Ugi Products

reserved5siA convergent and diversity-oriented approach to the unusual furo[2,3-c]isoquinoline scaffold is presented. This serendipity-driven approach is characterized by an Ugi multicomponent reaction, which gives the substrate for a palladium-catalyzed insertion-alkynylation-cycloisomerization cascade to provide the furo[2,3-c]isoquinolines in moderate to high yield. Upon UV excitation, all representatives are intensively blue luminescent, as observed by the naked eye, and quantitative fluorescence spectroscopy reveals a considerable effect of the substitution pattern on the quantum yields. The electronic structure is semiquantitatively rationalized by DFT and time-dependent DFT calculations.mixedMoni, L.; Gers-Panther, C.; Anselmo, M.; Müller, T. J. J.; Riva, R.Moni, Lisa; Gers Panther, C.; Anselmo, Manuel; Müller, T. J. J.; Riva, Renat

Solvatochromic Fluorescent 2‑Substituted 3‑Ethynyl Quinoxalines: Four-Component Synthesis, Photophysical Properties, and Electronic Structure

2-Substituted 3-ethynylquinoxalines can be rapidly synthesized in generally excellent yields by a consecutive four-component synthesis starting from electron-rich π-nucleophiles, oxalyl chloride, terminal alkynes, and 1,2-diaminoarenes. The title compounds are highly fluorescent with a pronounced emission solvatochromism. The photophysical properties and electronic structure were additionally corroborated by computations on the DFT level of theory

Solvatochromic Fluorescent 2‑Substituted 3‑Ethynyl Quinoxalines: Four-Component Synthesis, Photophysical Properties, and Electronic Structure

2-Substituted 3-ethynylquinoxalines can be rapidly synthesized in generally excellent yields by a consecutive four-component synthesis starting from electron-rich π-nucleophiles, oxalyl chloride, terminal alkynes, and 1,2-diaminoarenes. The title compounds are highly fluorescent with a pronounced emission solvatochromism. The photophysical properties and electronic structure were additionally corroborated by computations on the DFT level of theory

Four- and Five-Component Syntheses and Photophysical Properties of Emission Solvatochromic 3‑Aminovinylquinoxalines

3-Aminovinylquinoxalines are readily accessible from (hetero)­aryl glyoxylic acids or heterocyclic π-nucleophiles by consecutive four- and five-component syntheses in the sense of an activation-alkynylation-cyclocondensation-addition sequence or glyoxylation-alkynylation-cyclocondensation-addition sequence in good yields. The title compounds are highly fluorescent with pronounced emission solvatochromicity and protochromic fluorescence quenching. Time-resolved fluorescence spectroscopy furnishes radiative and nonradiative fluorescence decay rates in various solvent polarities. The electronic structure is corroborated by DFT and TD-DFT calculations rationalizing the observed spectroscopic effects