Tellurium atom, 6-membered heterocycles with

Six-membered heterocycles with one tellurium and two nitrogen atoms in the ring are represented by 2-aroyl derivatives of 1,2,3-telluradiazine and 5,6-benzo-1,2,3-telluradiazine 89. For the synthesis of these compounds, IV-aroylhydrazones of 2-bromotellurenylcyclohexenealdehyde and 2-bromotellurenylbenzaldehyde 90 were used as the starting materials (98ZOK959). Dehydrobromination of the hydrazones 90 occurs on treatment with triethylamine and gives the heterocycles 89 in about 80% yields. 

III. Bicyclic Six-Membered Heterocycles with a Tellurium Atom in Position 2. .. 53... 

Christiaens LEE (1996) Six-membered rings with one selenium or tellurium atom. In Katritzky AR, Rees CW, Scriven EFV (eds) Comprehensive heterocyclic chemistry II. Pergamon, Oxford, chap 5.11, p 619... 

The chemistry of six-membered heterocycles containing one selenium or tellurium atom was initially covered in CHEC-11(1996) (chapter 5.11). This updated chapter primarily deals with material dating from 1993 and is complete to 2005 with occasional references from 2006. The structures and nomenclature of the selenium- and tellurium-containing heterocycles discussed in this chapter are included in Figure 1. One major review of tellurium-containing heterocycles has appeared . The chemistry of thiopyrans, selenopyrans, and telluropyrans has also been reviewed <1994AHC180>. 

A number of theoretical studies of six-membered heterocycles containing one selenium or tellurium atom were previously described in CHEC-II(1996) (section 5.11.2). All of these consisted of ab initio calculations. Several new reports have appeared since this time dealing with theoretical approaches to understanding the properties of these materials, their preparations, and their reactivity. 

Aryl tellurium halides with suitable substituents in the ort/io-position to the tellurium atom cyclize to form heterocyclic compounds with tellurium as a ring-member. 

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