Tetramethyl Orthosilicate as a Sharp-Selective Catalyst of C3-Methylation of Indole by Supercritical Methanol
Научная публикация
| Общее |
Язык:
Английский,
Жанр:
Статья (Full article),
Статус опубликования:
Опубликована,
Оригинальность:
Оригинальная
|
| Журнал |
The Journal of Supercritical Fluids
ISSN: 0896-8446
, E-ISSN: 1872-8162
|
| Вых. Данные |
Год: 2012,
Том: 69,
Страницы: 82-90
Страниц
: 9
DOI:
10.1016/j.supflu.2012.05.013
|
| Ключевые слова |
3-Methylindole, Homogeneous catalysis, Indole methylation, Supercritical methanol, Tetramethyl orthosilicate |
| Авторы |
Kozhevnikov I.V.
1,2
,
Nuzhdin A.L.
1
,
Bukhtiyarova G.A.
1
,
Martyanov O.N.
1,2
,
Chibiryaev A.M.
2,3
|
| Организации |
| 1 |
Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrent’ev ave. 5, Novosibirsk 630090, Russia
|
| 2 |
Novosibirsk State University, Pirogova st. 2, Novosibirsk 630090, Russia
|
| 3 |
Vorozhtsov Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrent’ev ave. 9, Novosibirsk 630090, Russia
|
|
Информация о финансировании (1)
|
1
|
Российский фонд фундаментальных исследований
|
11-03-12049
|
Methylation reaction of indole was studied in supercritical methanol (350 °C, 215 atm) catalyzed by TMOS and TEOS. Use of both orthosilicates shows the same result of indole methylation. The indole conversion is ∼30% for 5 h of the reaction with and without catalysts. But catalytic reaction is more high-selective on 3-methyl-1H-indole formation – 95–96 mol% against 60 mol% for non-catalytic methylation. Indole conversion in catalytic reaction increases by a quarter (with no change of selectivity) when two equivalents of water are added into reaction mixture. Methylating system was assumed to be the TMOS–MeOH, and methylation proceeds via cyclic, multi-centered transition state (TS). The TS involves molecules of indole, TMOS, methanol, and water (if used), which are orientated in a certain way to each other by hydrogen and coordinate bonding. The reaction does not occur in supercritical ethanol or isopropanol with and without using the catalysts.