Micropores Induced Stereoselective Synthesis of E‐imines: Synergistic Effect between Cerium Species and Micropores in CeAlPO‐5 Molecular Sieves

Microwave-Assisted Synthesis of E-Aldimines, N-Heterocycles, and H2 by Dehydrogenative Coupling of Benzyl Alcohol and Aniline Derivatives Using CoCl2 as a Catalyst

The acceptorless dehydrogenative coupling (ADC) between alcohols and amines to produce imines has been achieved mostly by employing precious-metal-based complexes or complexes of earth-abundant metal ions with sensitive and complicated ligand systems as catalysts mostly under harsh reaction conditions. Methodologies using readily available earth-abundant metal salts as catalysts without the requirement of ligand, oxidant, or any external additives are not explored. We report an unprecedented microwave-assisted CoCl₂-catalyzed acceptorless dehydrogenative coupling of benzyl alcohol and amine for the synthesis of E-aldimines, N-heterocycles, and H₂ under mild condition, without any complicated exogenous ligand template, oxidant, or other additives. This environmentally benign methodology exhibits broad substrate scope (43 including 7 new products) with fair functional-group tolerance on the aniline ring. Detection of metal-associated intermediate by gas chromatography (GC) and HRMS, H₂ detection by GC, and kinetic isotope effect reveal the mechanism of this CoCl_2-catalyzed reaction to be via ADC. Furthermore, kinetic experiments and Hammett analysis with variation in the nature of substituents over the aniline ring reveal the insight into the reaction mechanism with different substituents.

Novel Recyclable Pd/H-MOR Catalyst for Suzuki-Miyaura Coupling and Application in the Synthesis of Crizotinib

In this paper, we report an effective ultrasound method for the synthesis of Pd/H-MOR, which was used as a catalyst in the Suzuki-Miyaura coupling of aryl halides with phenylboronic acid. The structure and morphology of the as-prepared catalysts were fully characterized by X-ray diffraction (XRD), N2 sorption isotherms, scanning electron microscopy (SEM), and an inductively coupled plasma-atomic emission spectrometer (ICP-AES). The advantages of Pd/H-MOR in the coupling reaction are green solvents, high yields, absence of ligands, and recyclability. The catalysts were easily reused at least ten times without significant deterioration in catalytic activity. In addition, this protocol was used in the marketed anti-tumor drug crizotinib synthesis.