One‐Pot Synthesis of Pyridyltellurium Derivatives from a Reaction with Isopropylmagnesium Chloride and X‐ray Crystal Structures of Various Pyridyl Ditellurides

Abstract

A one-pot synthesis of various symmetrical and unsymmetrical 2-pyridyl-, 2-bromo-5-pyridyl-, and 2,5-dibromo-3-pyridyltellurium compounds has been carried out, at room temperature, by selective single bromine-magnesium exchange of 2-bromo-, 2,5-dibromo-and 2,3,5-tribromopyridine, respectively, with isopropylmagnesium chloride. This exchange reaction gives the corresponding pyridylmagnesium chlorides, which, upon insertion of elemental tellurium (activated), give the pyridyltelluromagnesium chlorides, and,

Synthesis and characterization of novel pyridyl/naphthyl/(diphenyl)methylseleno substituted alkanoic acids: X-ray structure of 2-pyridylselenoethanoic acid, 2-naphthylselenoethanoic acid and 2-(diphenyl)methylselenoethanoic acid

“…Starting substrates, dipyridyl/dinaphthyl/bis(diphenylmethyl) diselenide (1-6) were prepared using the reported procedure [41][42][43][44][45][46]. Commercially available reagents such as ethyl 2-chloroethanoate 7a, ethyl 3-chloropropanoate 7b and ethyl 4-chlorobutanoate 7c were used as such without further purification.…”

“…In addition, successful attempts have also been made towards the design, synthesis and structural studies of symmetrical and unsymmetrical organochalcogens in our laboratory [41][42][43][44][45][46].…”

Metalated heterocycles in organic synthesis: Recent applications

“…436 Other tellurium-substituted heterocycles have been obtained by a S N Ar reaction using sodium arenetellurate ions, generated in situ by the reduction of diarylditelluride with sodium borohydride, as it is the case of the triazine 236, prepared by this method from 2,4,6-trichloro-1,3,5-triazine. 437 In addition, β-organotellurobutenolides, such as compound 237, have been prepared by electrophilic tellurolactonization of α-allenoic acids, and have been used in both substitution reaction with cuprates or in palladium-catalyzed Sonogashira cross-coupling reactions.…”

Bis(4-pyridyl)ditelluride as starting material for the synthesis of zwitterionic compounds and metal complexes

“…More recently, Bhasin and coworkers published a one-pot synthetic approach to various pyridyl ditellurides and the X-ray crystal structures of several representatives [25]. The use of synthons containing a pyridyl subunit attached to a chalcogen atom is a very interesting strategy for coordination chemistry owing the different nature of the existent binding sites.…”

“…Despite of these very interesting characteristics, just a few examples of such compounds are known. This fact can be related with the difficulty to generate such compounds directly from the corresponding halides in good yields [25]. In the last 20 years, we could observe an increasing interest in this kind of ligands, and the most common complexes found in the literature were prepared from the 2-telluro derivatives.…”