A novel and facile one-pot synthesis of pyridylselenium compounds through selective bromine–magnesium exchange with isopropylmagnesium halide

Abstract

One-pot synthesis of various unsymmetrical 2-bromo-5-pyridylselenium compounds has been carried out under non-cryogenic conditions by selective single bromine-magnesium exchange of 2,5-dibromopyridine using isopropylmagnesium chloride. This exchange gives 2-bromo-5-pyridylmagnesium chloride, which upon the insertion of elemental selenium followed by the treatment with alkyl halide gives the title compounds in good yield. This exchange has also been extended towards bromine-magnesium exchange of 2-bromopyridine for the improved synthesis of 2-pyridylselenium compounds. The molecular structure of 2-bromo-5-selenopyridyltribromomethane has been examined by single crystal X-ray diffraction. This compound crystallizes in the monoclinic space group P2 1 /n. From the molecular structure it was found that intermolecular Br· · ·Br, N· · ·Se and Se· · ·Br interactions control its crystal packing.

The synthesis, crystal structures and SOD activities of a new ligand (Lse) and Co(Lse)2(SCN)2 complex [Lse = selenium ether bis‐(N‐1‐methyl‐ benzotriazole)]

“…5 -11 However, most reports concern the organoselenium compound, and the coordination of selenolates as a ligand has not been widely studied. The metal complexes with ligands containing selenium and nitrogen donors are interesting for several reasons: 12 first, they can provide insight into the competitive coordination behavior between the hard and soft Lewis basic nitrogen and selenium towards the same metal center; and second, whether the biological activity of the selenium increases or not under the action of metal ions in the same compound and the interaction of selenium with metal ions in a same complex is a subject worth studying.…”

In Situ Formation of Pyridyl-Functionalized Poly(3-hexylthiophene)s via Quenching of the Grignard Metathesis Polymerization: Toward Ligands for Semiconductor Quantum Dots

“…The pyridyl-Grignard reagents were prepared by metal–halogen exchange of the corresponding bromopyridines with isopropyl magnesium chloride ( i -PrMgCl) in the presence of lithium chloride (LiCl), according to a modified literature procedure. − Initial attempts to synthesize the pyridyl Grignard reagents without LiCl resulted in low yields for the 2-pyridyl Grignard or seemingly unsuccessful synthesis of the 3- and 4-pyridyl Grignard compounds. Interestingly, we observe that the 3-pyridyl Grignard reagent precipitates from solution if LiCl is not used during its preparation, yielding a highly reactive solid.…”

Emerging trends in organotellurolate chemistry derived from platinoids

“…In contrast, the stability and ease of handling of aryl magnesium bromide compounds makes this synthetic strategy quite trendy. Normally for all cases, a Grignard reagent of the corresponding alkyl or arylhalo compounds is rst synthesized, 36,37,50,51 followed by the insertion of elemental tellurium, which on acid hydrolysis yields the corresponding ditellurides in a moderate yield.…”