- Preparation of acylthiophenes by iron(III) chloride catalyzed reactions of tris(2-thienyl)stibanes with acyl chlorides
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The reactions of tris(2-thienyl)stibanes with various acyl chlorides, using a catalytic amount of iron(III) chloride, afforded 2-acylthiophenes. Iron(III) chloride is presumed to act as a Lewis acid, and the ipso substituent of each 2-thienyl group of tris(2-thienyl)stibane is replaced with an acyl group. The reaction is highly atom-efficient in that all three thiophene rings of tris(2-thienyl)stibane take part in the reaction. The reaction procedure is so simple that it can also be carried out under solvent-free and aerobic conditions.
- Kakusawa, Naoki,Nakagawa, Yoshie,Toshima, Yutarou,Yasuike, Shuji,Kurita, Jyoji
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p. 1170 - 1175
(2015/07/15)
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- Comparative performance evaluation and systematic screening of solvents in a range of Grignard reactions
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The solvent effect on the Grignard reaction of benzyl, aryl and heteroaromatic substrates has been systematically evaluated based on reaction efficiency, ease of subsequent work-up, safety and greenness. 2-Methyltetrahydrofuran (2-MeTHF), which can be derived from renewable resources, had at least an equal if not a superior overall process most notably in suppressing the Wurtz coupling by-product from the benzyl Grignard reactions. It is therefore a recommended alternative solvent to Et2O and THF for the preparation of most Grignard reagents and their subsequent reactions.
- Kadam, Asha,Nguyen, Mylinh,Kopach, Michael,Richardson, Paul,Gallou, Fabrice,Wan, Zhao-Kui,Zhang, Wei
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p. 1880 - 1888
(2013/09/24)
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- Highly selective 5-substitution of 3-methylthiophene via directed lithiation
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(Chemical Equation Presented) Lithiation of 3-methylthiophene with lithium 2,2,6,6-tetramethylpiperidide (LiTMP) is highly selective at the 5-position, and reaction with a range of electrophiles gives high yields of the corresponding 2,4-disubstituted thiophenes, even when unhindered electrophiles are used.
- Smith, Keith,Barratt, Mark Lewis
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p. 1031 - 1034
(2008/02/04)
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- A highly active ytterbium(III) methide complex for truly catalytic Friedel-Crafts acylation reactions
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The Friedel-Crafts acylation of anisole with acetic anhydride using ytterbium(III) tri[tris(nonafluorobutanesulfonyl)methide] was studied with respect to catalyst loading. A strong inhibitory effect due to the product became apparent from doping experiments and from examination of the kinetic data. This understanding allowed catalyst loadings to be reduced to as little as 0.1 mol% for effective acylation under a suitable temperature and pressure regime.
- Barrett, Anthony G. M.,Bouloc, Nathalie,Braddock, D. Christopher,Chadwick, David,Henderson, David A.
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p. 1653 - 1656
(2007/10/03)
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