87167-64-4Relevant academic research and scientific papers
Synthetic Studies of Indoles and Related Compounds, Part 221. The Vilsmeier-Haack Reaction of N-Benzyl-1,2,3,4-tetrahydrocarbazoles and its Synthetic Application to Olivacine and Ellipticine2
Yokoyama, Yuusaku,Okuyama, Naomi,Iwadate, Shinji,Momoi, Tokuko,Murakami, Yasuoki
, p. 1319 - 1329 (2007/10/02)
Vilsmeier-Haack reaction of 9-benzyl-1,2,3,4-tetrahydrocarbazole (18a) at 120 deg C gave 9-benzyl-1-methylcarbazole-3-carbaldehyde (19a) and 9-benzyl-1-(N,N-(dimethylamino)methyl)carbazole-3-carbaldehyde (22a) in moderate yields, whereas, the same reaction at 0 deg C gave 9-benzyl-1,2,3,4-tetrahydrocarbazole-1-carbaldehyde (20a) in very good yield.The aldehyde (20a) was converted into 9-benzyl-1-methylcarbazole (21a) by another Vilsmeier-Haack reaction.This carbazole (21a) unexpectedly underwent non-regioselective formylation under similar reaction conditions to give a mixture of compound (19a) and 9-benzyl-8-methylcarbazole-3-carbaldehyde (23a).On the basis of the above results, a mechanism of the formation of the aromatic aldehyde (19a) was proposed, which involves 1,5-sigmatropic rearrangement of an N-methylidene dimethylammonium cation from the 4a-position to the 3-position as a key step.Vilsmeier-Haack reaction of 9-benzyl-1,2,3,4-tetrahydro-4-methylcarbazole (18b) at 100 deg C also gave 9-benzyl-1,4-dimethylcarbazole-3-carbaldehyde (19b) in moderate yield.The total syntheses of two antitumor alkaloids, olivacine (10) and ellipticine (11), were achieved by utilizing compounds (19a) and (19b) as key intermediates.
REGIOSELECTIVITY IN THE VILSMEIER-HAACK REACTION OF N-BENZYL-1,2,3,4-TETRAHYDROCARBAZOLE
Murakami, Yasuoki,Yokoyama, Yuusaku,Miura, Tomoko,Nozawa, Sumiko,Takeda, Emiko,Suzuki, Hideharu
, p. 2341 - 2344 (2007/10/02)
The Vilsmeier-Haack reaction of N-benzyl-1,2,3,4-tetrahydrocarbazole (1) with various N,N-disubstituted formamides (6) and phosphorous oxychloride took place not only on the alicyclic portion but also on the benzene moiety depending on the reactivity and
THE VILSMEIER-HAACK REACTION OF N-ALKYL-1,2,3,4-TETRAHYDROCARBAZOLES AND THE SYNTHETIC APPLICATION TO OLIVACINE AND ELLIPTICINE
Murakami, Yasuoki,Yokoyama, Yuusaku,Okuyama, Naomi
, p. 2189 - 2192 (2007/10/02)
The mechanism of the formation of products resulting from the Vilsmeier-Haack reaction of N-alkyl-1,2,3,4-tetrahydrocarbazoles, and the synthetic application to olivacine and ellipticine, are described.
