Reactions of group 13 metal trialkyls with oxamides

Abstract

Alkyl aluminum-, gallium-, and indium oxamidates Me 4Al 2(dpoa) ( 1), Me 4Al 2(dboa) ( 2), Me 4Ga 2(dpoa) ( 3), Me 4Ga 2(dboa) ( 4), t Bu 4Ga 2(dpoa) ( 5) and Me 4In 2(dboa) ( 6) (dpoa-H 2 = N, N′-diphenyloxamide, dboa-H 2 = N, N′-di- tert-butyloxamide) have been prepared and characterized. Compounds 1– 3, 5 and 6 exist in the form of isomers a only, with a skeleton framework of the molecules consisting of two almost flat, coplanar and fused MNOC 2 (M = Al, Ga, In) heterocyclic rings. Depending on the reaction conditions, the compound 4 was obtained as the isomer 4a or as the mixture of two isomers 4a and 4b. Molecular structures of the compounds 1a– 6a have been determined by X-ray crystallography. A structure of the isomer 4b was proposed on the basis of NMR spectroscopy. A skeleton framework of the 4b molecule consists of two fused different cycles, GaO 2C 2 and GaN 2C 2.