126774-93-4Relevant academic research and scientific papers
Efficient syntheses of substituted carbazoles and cyclopent[b]indoles from 1-methyl-3-(benzotriazol-1-ylmethyl)indole
Katritzky, Alan R.,Zhang, Guifen,Xie, Linghong,Ghiviriga, Ion
, p. 7558 - 7563 (1996)
1-Methyl-3-(benzotriazol-1-ylmethyl)indole (1) undergoes lithiation and 1,4-addition with a variety of α,β-unsaturated ketones and aldehydes. Subsequent treatment with an acidic resin in refluxing 1,4-dioxane causes intramolecular cyclization followed by aromatization to furnish a wide range of 1,3-di-, 2,3-di-, and 1,2,3-trisubstituted carbazoles 6a-j and 8 in moderate to excellent yields. NMR study is described to discriminate between structures of types 6 and 8 on the basis of 1H-13C long-range correlation. Treatment of 1 with styrenes in the presence of zinc bromide results in formal [3 + 2] cycloaddition to give cyclopent[b]indoles 14a-c in good yields. When 1 is first lithiated and reacts with electrophiles, the resulting alkylation products undergo similar [3 + 2] additions with styrenes to give 1-functionalized cyclopent[b]indoles 15 and 16 with a high degree of stereoselectivity.
Diels-Alder Reactions of Pyranoindol-3-ones and a 2-Benzopyran-3-one with Hetero Substituted Olefins: Generation of Carbazole and Naphthalene Derivatives by Elimination instead of Dehydrogenation
Broeck, Peter I. Van,Doren, Philippe E. Van,Toppet, Suzanne M.,Hoornaert, Georges J.
, p. 415 - 420 (2007/10/02)
Pyranoindol-3-ones are shown to undergo cycloaddition with electron-rich olefins.However, after loss of CO2 from the adducts, the intermediate indole-2,3-quinodimethanes are not dehydrogenated - after a 1,5-sigmatropic hydrogen shift - to yield the
DIELS-ALDER REACTIONS OF PYRANOINDOL-3-ONES WITH OLEFINIC COMPOUNDS : SYNTHESIS OF (1,2-DIHYDRO)CARBAZOLES
Doren, P. van,Vanderzande, D.,Toppet, S.,Hoornaert, G.
, p. 6761 - 6770 (2007/10/02)
The Diels-Alder reaction of substituted pyrano indol-3-ones 1 with olefinic dienophiles is described.The role of the substitution pattern on the stability of the obtained 1,2-dihydrocarbazoles is interpreted in terms of electronic and steric effect
