Oxatellurol-l-ium Halides

2- oxatellurol-l-ium chlorides 3, the five-membered ring of which contains a re-electron sextet and, therefore, acquires substantial aromatic character. 

The above method for the synthesis of heterocycles 3 has some shortcomings, such as its multistep character, applicability to only Te-aryl derivatives and unsuitability for the preparation of the compounds 3 containing a substituent in the position 4 of 

In the case of dichlorotellurochromanone 13 (X = Cl), the final product of this reaction is 2-(acryloyl)phenyltellurenyl chloride 15 formed in 80% yield by the elimination of a molecule hydrogen chloride from the intermediate 2-(/i-prop-ionyl)phenyltellurenyl chloride 14 (X = Cl). 

By coupling u-bromotellurenylacetophenone with benzaldehydes telluroaurones (arylidene-2-dihydro-2,3-oxo-3-benzo[7 ]tellurophenes) 26 were obtained in 80% and 

Ar=2-C1C6H4, 4-ClC6H4, 4-IC6H4,4-MeC6H4,4-MeOC6H4,4-Me2NC6H4, 

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Halogenotellurenylvinyl aldehydes (1,2-oxatellurol-l-ium halides) 8 and 9 readily react with aromatic amines to give A-aryh/l-halogenotellurenylvinyl imines (N-aryl-l,2-azatellurol-l-ium halides) 38 in high yields (96ZOK1434) (Scheme 22). 

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