We report the synthesis of highly stable NLO active new chromophores substituted with triazolo[3,4-b]-thiadiazole
heterocycles. With these, a series of second-order NLO responsive polyurethanes were successfully prepared by condensation with tolylene-2,4-diisocyanate and 4,4'-methylenedi(phenyl isocyanate).
Montalban,
Heterocycles in Natural Product Synthesis, Wiley-VCH, New York, NY, USA, 2011, 299-339.
Alonso and coworkers synthesized 1,2,3-triazoles through various
heterocycles derived from natural product such as (-)-menthol, lactic acid, D-glucose, oestrone, and cholesterol converting them into alkynes by introducing propargyl groups.
The activity of the alkylated
heterocycles S1-S5 (see Supplementary Material) is sufficient enough to selectively react with the corresponding dianils S6 and S7 to its half dyes S11-S16 while the second condensation reaction step to the symmetrical full dye is prevented.
From the theoretical point, the differences in the stability of
heterocycles are explained in terms of aromaticity and delocalization of electron densities on [pi] molecular orbitals.
Among the many species of bamboo, Moso bamboo (Phyllostachys
heterocycle Milf, Phyllostachys pubescens Mazel ex H.
Chaskar, Relevance of sonochemistry or ultrasound (US) as a proficient means for the synthesis of fused
heterocycles, Ultrason.
The literature survey itself covers transition metal-catalyzed reactions, miscellaneous organic transformations,
heterocycle synthesis, and combinatorial chemistry and high-throughput organic synthesis.
Reaction of 5 with pyridazine generates a polycyclicaromatic hydrocarbon analog (7) in which the central
heterocycle is a [C.sub.2][B.sub.2][N.sub.2] ring.
The discovered novel methodology involved sequential multicomponent reactions; consisting of Knoevenagel reaction followed by Michael addition; moreover, the proposed mechanism is consistent with the stepwise methodology which also availed the same tricyclic
heterocycle compounds (1c-6c) and (1d-7d).
Isoquinoline, the bicyclic aromatic
heterocycle shown in Figure 1, was first isolated as the sulfate salt from coal tar in 1885 by Hoogewerf and van Dorp [1].
Among their topics are recyclable organocatalysts in asymmetric reactions, the synthesis of chiral catalysts supported on organic polymers, asymmetric catalytic synthesis in supercritical fluids, microwave-assisted transition metal-catalyzed asymmetric synthesis, silicate-mediated stereoselective reactions catalyzed by chiral Lewis bases, and stereoselective nitrogen
heterocycle synthesis mediated by chiral metal catalysts.
