Tetramethyl Orthosilicate as a Sharp-Selective Catalyst of C3-Methylation of Indole by Supercritical Methanol | Sciact - CRIS-system of Boreskov Institute of Catalysis

Tetramethyl Orthosilicate as a Sharp-Selective Catalyst of C3-Methylation of Indole by Supercritical Methanol Full article

Journal

The Journal of Supercritical Fluids
ISSN: 0896-8446 , E-ISSN: 1872-8162

Output data

Year: 2012, Volume: 69, Pages: 82-90 Pages count : 9 DOI: 10.1016/j.supflu.2012.05.013

Tags

3-Methylindole, Homogeneous catalysis, Indole methylation, Supercritical methanol, Tetramethyl orthosilicate

Authors

Kozhevnikov I.V. ^1,2 , Nuzhdin A.L. ¹ , Bukhtiyarova G.A. ¹ , Martyanov O.N. ^1,2 , Chibiryaev A.M. ^2,3

Affiliations

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

Funding (1)

Russian Foundation for Basic Research

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.

Kozhevnikov I.V. , Nuzhdin A.L. , Bukhtiyarova G.A. , Martyanov O.N. , Chibiryaev A.M.
Tetramethyl Orthosilicate as a Sharp-Selective Catalyst of C3-Methylation of Indole by Supercritical Methanol
The Journal of Supercritical Fluids. 2012. V.69. P.82-90. DOI: 10.1016/j.supflu.2012.05.013 WOS Scopus РИНЦ ANCAN OpenAlex

Submitted:	Mar 9, 2012
Accepted:	May 23, 2012
Published online:	Jun 2, 2012
Published print:	Sep 1, 2012

Web of science:	WOS:000307414100011
Scopus:	2-s2.0-84863950092
Elibrary:	20477417
Chemical Abstracts:	2012:1039806
Chemical Abstracts (print):	157:467861
OpenAlex:	W1998030343

DB	Citing
Web of science	7
Scopus	7
Elibrary	9
OpenAlex	6