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Thiocyanation of N-arylaminocarbonyl-1,4-benzoquinonemonoimines
Authors: S.A. Konovalova, A.P. Avdeenko, A.G. Sergeeva, S.A. Goncharova, M.V. Polischuk
Number of views: 496
The 1,4-binding of a thiocyanate-ion at the thiocyanation of N-substituted 1,4-benzoquinonmonoimines via a sulfur atom has been earlier suggested to be typical of quinonmonoimines with low LUMO energy, whereas such binding proceeds via a nitrogen atom of thiocyanate for quinonmonoimines with high LUMO energy. The thiocyanation of N-arylaminocarbonyl-1,4-benzoquinonemonoimines leads to the formation of 1,3-benzoxathiol-2-ones and 2-imino-1,3-benzoxathioles which are obtained through the initial 1,4-binding of a thiocyanate-ion via a sulfur atom, 1,3-benzoxathiol-2-ones being the products of hydrolysis of 2-imino-1,3-benzoxathioles. According to the quantum-chemical calculations, the N-arylaminocarbonyl-1,4-benzoquinonemonoimines have lower LUMO energy than N-acetyl- and N-phenilacetyl-1,4-benzoquinonemonoimines, the latter give the products of binding both via a sulfur atom and via a nitrogen one. This confirms the fact that the LUMO energy of an initial quinonemonoimine is a key factor in the thiocyanation of N-substituted 1,4-benzoquinonmonoimines, the binding of thiocyanate-ions proceeds via a sulfur atom under orbital control.