Kuladip Sarma

Microwave-assisted synthesis of 3-sulfenylindoles by sulfonyl hydrazides using organic ionic base-Brønsted acid

A novel, efficient, and high-yielding method was developed for the synthesis of 3-sulfenylindoles via a DBU-based ionic liquid promoted sulfenylation of indoles using sulfonyl hydrazides as a thiol surrogate. The environmentally friendly procedure, easy operation and mild reaction conditions enable the tolerance of a wide scope of functionalities as well as high reaction efficiency. The synthetic procedure is suitable for both N-protected or unprotected indoles.

Nickel(II), copper(II), cobalt(II), and palladium(II) complexes with a Schiff base: crystal structure, DFT study and copper complex catalyzed aerobic oxidation of alcohol to aldehyde

Ni(II), Cu(II), Co(II), and Pd(II) complexes were synthesized with a Schiff base containing thioether with ONS donors chelating to the metal center. The ligand and complexes were characterized by elemental analysis, FT-IR, 1H-NMR, UV–visible spectroscopy and magnetic studies. The crystal structures of the ligand and its Ni(II) and Pd(II) complexes were determined by single-crystal X-ray diffraction analysis. Structures revealed that the ligand chelated with Ni(II) and Pd(II) center in slightly distorted octahedral and slightly distorted square planar fashion, respectively. DFT studies of the Pd(II) complex revealed that the calculated structural parameters are very close with the experimentally observed data. The Cu(II) complex shows very good catalytic activity toward the conversion of alcohol to aldehyde under aerobic oxidation with ammonium persulfate.

An Efficient Method for One-Pot Reductive Cleavage of Acetals to Primary Alcohols Using a Bimetal Redox Couple CoCl2.6H2O-Zn

Acyclic or cyclic O,O-acetals and O,S-acetals underwent reductive cleavage to give primary alcohols efficiently on treatment with Zn-CoCl2.6H2O-bimetal redox system in dry tetrahydrofuran at ambient temperature to give good to excellent yields.