C 98 Cyclizations of N-alkyl-substituted azinium cations with bifunctional nucleophiles. 28. Orientation of the nucleophile in the reaction of quinoxalinium salts with indan-1,3-dione [Electronic resource] / G. M. Petrova, M. G. Ponizovskii, V. N. Charushin, G. G. Aleksandrov, E. O. Sidorov, O. N. Chupakhin // Chemistry of Heterocyclic Compounds. - 1990. - Vol. 26, № 5. - С. 565-572. - Bibliogr. : p. 572 (12 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): QUINOXALINUM SALTS -- C-NUCLEOPHILES -- AZINIUM CATIONS Аннотация: In reactions with quinoxalinium salts in alcoholic-base media indan-1,3-dione acts as a C nucleophile, adding at the 2 or 3 position of the heterocycle to give the corresponding ylidene derivatives; attack by the nucleophile at the C(3) atom (the Β position relative to the quaternary nitrogen atom) is preceded by addition of alcohol at the a position. Dissociative substitution at the C(2) atom in 2-alkoxy-3-(1,3-dioxoindan-2-ylidene)-1,2,3,4-tetrahydroquinoxalines by another nucleophile makes it possible to regard lyate complexes as probable intermediates in cyclizations of 1,4-diazinium salts with dinucleophiles. \\\\expert2\\nbo\\Chemistry of Heterocyclic Compounds\\1990, v.26, N 5, p.565.pdf |