Zinc Oxide Nanoparticles Catalyzed Condensation Reaction of Isocoumarins and 1,7-Heptadiamine in the Formation of Bis-Isoquinolinones

The diversified bis-isoquinolinones were obtained in two steps, utilizing homophthalic acid and various acid chlorides providing 3-substituted isocoumarins in the first step which on further condensation with 1,7-heptadiamine involving C–N bond formation from the lactone in the presence of 10 mol% zinc oxide nanoparticles (ZnO NPs) (<150 nm) afforded the desired bis-isoquinolinones in high yield and purity. The synthesized compounds were then characterized using FTIR, 1H NMR, 13C NMR, and HRMS techniques

Ruthenium-Catalyzed Deoxygenative Hydroboration of Carboxylic Acids

An efficient deoxygenative hydroboration of carboxylic acids to alkyl boronate esters under mild reaction condition is reported. Both aromatic and aliphatic carboxylic acids exhibited excellent reactivities with minimal catalyst load of 0.1 mol % and reactions occurred under neat conditions. This catalytic transformation selectively provides alkyl boronate esters, which can be conveniently hydrolyzed to obtain the corresponding alcohols. Remarkably, this reduction reaction proceeds with the liberation of molecular hydrogen

Selective α‑Deuteration of Amines and Amino Acids Using D₂O

Monohydrido-bridged ruthenium complex [{(η⁶-<i>p</i>-cymene)­RuCl}₂(μ-H-μ-Cl)] catalyzes (catalyst load: 0.5–1 mol %) α-selective deuteration of primary and secondary amines, amino acids, and drug molecules using deuterium oxide (D₂O) as a deuterium source. Mechanistic investigations revealed N–H activation of amines, which was also established by single-crystal X-ray analysis of an intermediate. β-Hydride elimination on amide ligand results in formation of imine-ligated ruthenium intermediate and subsequent 1,3-deuteride migrations to imine ligand leading to the selective deuteration at the α-CH₂ protons of amine functionality is proposed

Ruthenium-Catalyzed Urea Synthesis by N–H Activation of Amines

Activation of the N–H bond of amines by a ruthenium pincer complex operating via “amine–amide” metal–ligand cooperation is demonstrated. Catalytic formyl C–H activation of <i>N</i>,<i>N</i>-dimethylformamide (DMF) is observed in situ, which resulted in the formation of CO and dimethylamine. The scope of this new mode of bond activation is extended to the synthesis of urea derivatives from amines using DMF as a carbon monoxide (CO) surrogate. This catalytic protocol allows the synthesis of simple and functionalized urea derivatives with liberation of hydrogen, devoid of any stoichiometric activating reagents, and avoids the direct use of fatal CO. The catalytic carbonylation occurred at low temperature to provide the formamide; a formamide intermediate was isolated. The consecutive addition of different amines provided unsymmetrical urea compounds. The reactions are proposed to proceed via N–H activation of amines followed by CO insertion from DMF and with liberation of dihydrogen

Green Chemical Approach: Low-Melting Mixture as a Green Solvent for Efficient Michael Addition of Homophthalimides with Chalcones

Employing Burkhard Konig’s l-(+)-tartaric acid-dimethyl urea (DMU) mixture as an efficient catalyst or as solvent for the Michael addition of various chalcones with <i>N</i>-arylhomophthalimides could successfully furnish the corresponding 4-subtituted-<i>N</i>-arylhomophthalides under mild conditions. The melts were found to be inexpensive, nontoxic, simple to use, high yielding, reusable, and biodegradable

Thiourea-Mediated Regioselective Synthesis of Symmetrical and Unsymmetrical Diversified Thioethers

An efficient and simple thiourea-mediated regioselective synthesis of symmetrical and unsymmetrical diversified thioethers is reported. The regioselective reaction avoids byproduct formation and offers simplified methodology, wider applicability, and easy workability and an environmentally friendly approach toward symmetrical and unsymmetrical thioethers. The mechanism of formation of thiols and symmetrical and unsymmetrical thioethers involving a sulfur surrogate is described