S 98 Synthesis of 4-(thien-2-yl)-substituted coumarins through Lewis acid catalyzed Michael addition of thiophenes to 3-benzoylcoumarins followed by oxidation [Electronic resource] / R. A. Irgashev, A. A. Karmatsky, G. L. Rusinov, V. N. Charushin // Tetrahedron Letters. - 2014. - Vol.55, №26. - С. 3603-3606 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): THIOPHENES -- 3-BENZOYLCOUMARINS -- Lewis acid Аннотация: 3-Benzoyl-4-(thien-2-yl)coumarins have been obtained in good yields according to the SNH addition–oxidation protocol, involving the diastereoselective addition of thiophenes at C-4 of 3-benzoylcoumarins under BBr3 catalysis, followed by oxidation of the intermediate 3,4-trans-3-benzoyl-4-(thien-2-yl)-3,4-dihydrocoumarins with DDQ. This two-step procedure can be regarded as nucleophilic substitution of hydrogen (SNH) on the heterocyclic ring of coumarins \\\\expert2\\nbo\\Tetrahedron Letters\\2014, v. 55, p. 3603.pdf |
M 61 Metal-free synthesis of 4-(thien-2-yl) substituted coumarins through direct C-H/C-H coupling of 3-benzoylcoumarins with thiophenes / A. A. Karmatsky, R. A. Irgashev, G. L. Rusinov, V. N. Charushin // Уральский научный форум "Современные проблемы органической химии". XVII Молодежная школа-конф. по органической химии, Екатернинбург, 8-12 июня 2014 г. : сб. тез. - Екатеринбург, 2014. - С. 154. - Библиогр.: с. 154 (2 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): SYNTHESIS -- THIOPHENES -- AROYLCHROMONES |