New palladium(II) N,N,O-pincer type complexes promoted one pot cascade synthesis of quinazolines through dehydrogenative coupling of easily available alcohols and 2-aminobenzylamine has been reported. A distinct set of Pd(II)...

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A facile catalytic one‐pot synthesis of N‐acylhydrazones via acceptorless dehydrogenative coupling of readily available alcohols and benzohydrazides (R2CONHNH2) using arene ruthenium (II) complexes has been described. The coupling of alcohols with various benzohydrazides using ruthenium catalysts provide a wide range of N‐acylhydrazones in good to excellent yields (63–93%; 32 examples). The present protocol offers high selectivity of hydrazones without any alkylated products and tolerates a range of functional groups. Control experiments indicate that the mechanism proceeds via acceptorless dehydrogenation of alcohols, and hydrogen and water are the sole by‐products. The gram scale synthesis illustrates the usefulness of the present strategy.

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An efficient Pd(II)N^N^S pincer type catalysts‐promoted sustainable construction of pharmaceutically important benzothiazole derivatives from primary alcohols and 2‐aminothiophenol via acceptorless dehydrogenative coupling (ADC) method has been described. The newly synthesized ligand L2 and the Pd(II) complexes in addition to L1 and L3 were characterized by analytical and Fourier transform infrared spectroscopy (FT‐IR), UV–visible (UV–vis), and nuclear magnetic resonance (NMR) spectral techniques. Further, the ORTEP views of the complexes 2 and 3 were established by a single crystal XRD study, which evidenced the coordination of the thiosemicarbazone ligands and disclose the square‐planar geometry around the Pd(II) ion. The present homogeneous catalytic system involves synthesizing a range of benzothiazoles via C−S and C−N bond formation with excellent yields up to 93%. The described methodology employs a sustainable, highly abundant, and inexpensive alcohol as starting material using 1 mol% catalyst loading, and water and hydrogen gas are the only by‐products. Furthermore, a plausible mechanism involving in situ aldehyde formation via dehydrogenation of primary alcohols has been proposed. A large‐scale synthesis of 2‐(4‐methoxyphenyl)benzo[d]thiazole illustrates the synthetic utility of the present catalytic protocol.