Mild, convenient and efficient synthesis of novel 2,2-dichloro-1,3-diarylaziridines from Schiff bases by phase transfer CTAB catalysis under low concentration alkaline conditions

Ultrasonic assisted synthesis of gem-dichloroaziridine derivatives using Mg/CCl4 under neutral conditions

A novel and convenient method for synthesis of gem-dichloroaziridine derivatives was reported in that was utilized Mg powder with CCl4 for dichlorocarbene generation under ultrasonic irradiation. In this clean and efficient reaction procedure, the desired products were purely obtained in excellent yields. The other advantages of this method are availability of reagents, very short reaction times, simplicity of the method, easily work up, neutral reaction medium and high purity of products.

Synthesis, X-ray structure, spectroscopic properties and DFT studies of a novel Schiff base

A series of Schiff bases, salicylideneaniline derivatives 1-4, was synthesized under mild conditions and characterized by 1H NMR, HRMS, UV-Vis and fluorescence spectra, and single-crystal X-ray diffraction. In solid and aprotic solvents 1-4 exist mainly as E conformers that possess an intramolecular six-membered-ring hydrogen bond. A weak intramolecular C-H···F hydrogen bond is also observed in fluoro-functionalized Schiff base 4, which generates another S(6) ring motif. The C-H···F hydrogen bond further stabilizes its structure and leads it to form a planar configuration. Compounds 1-3 exhibit solely a long-wavelength proton-transfer tautomer emission, while dipole-functionalized Schiff base 4 shows remarkable dual emission originated from the excited-state intramolecular charge transfer (ESICT) and excited-state intramolecular proton transfer (ESIPT) states. Furthermore, the geometric structures, frontier molecular orbitals (MOs) and the potential energy curves for 1-4 in the ground and the first singlet excited state were fully rationalized by density functional theory (DFT) and time-dependent DFT calculations.