Non-Pincer-Type Arene Ru(II) Catalysts for the Direct Synthesis of Azines from Alcohols and Hydrazine under Aerobic Conditions
作者:Sundar Saranya、Rengan Ramesh、David Sémeril
DOI:10.1021/acs.organomet.0c00367
日期:2020.9.14
tandem approach to synthesize symmetrical azinesfrom alcohols and hydrazine hydrate catalyzed by synthesized arene Ru(II) complexes of aroylthiourea ligand. Notably, the catalytic efficiencies of six- and four-membered N,S-chelate ruthenium complexes were evaluated. The catalytic reaction exhibits complete selectivity for symmetrical azines. A diverse range of azines was synthesized in good to high yields
acetonitrile, yielding predominantly the kinetic cis-configured adduct as a racemate. Thermodynamically more stable trans-configuration could be attained either via heating the cis-configured product in DMSO or via the action of a base (imidazole) in the course of CDI-promoted esterification or amidation of the carboxylic acid function in the initial adducts. Further manipulation of the remaining N-acylhydrazone
The syntheses, characterizations and structural determinations of N,N′-bis(thiophenyl-2-methylene)hydrazine 1, N,N′-bis(4-bromothiophenyl-2-methylene)hydrazine 2 and N,N′-bis(5-bromothiophenyl-2-methylene)hydrazine 3 are presented. The materials show third-order nonlinear behaviour with transmissions of 20, 22 and 18 μJ for an input energy of 150 μJ. The 4- and 5-bromothiophenic structures show Br⋯Br interactions of 3.562 and 3.626 Å, respectively. Analysis of bromine containing aromatic compounds in the Cambridge Crystallographic Database (CSD) showed the expected angle dependences of the Br⋯Br interactions dividing these into “type I” and “type II”. A semi-quantitative agreement was found between the CSD data and a model derived form calculated electrostatic potentials.
Ionic hydrogenation of azines: An efficient synthesis of 1,2-dialkylhydrazines
作者:Dario Perdicchia
DOI:10.1016/j.tet.2023.133432
日期:2023.6
An efficient synthetic method of ionic hydrogenation of azine to the corresponding 1,2-dialkylhydrazines was accomplished. Reaction time was fast and isolation and purification of the 1,2-dialkylhydrazines were operationally simple. Yields were almost quantitative for most of the products with good functional group tolerance. Moreover, the byproduct of reduction gave the opportunity for the selective