- Ru(ii)-catalyzed intermolecular ortho-C-H amidation of aromatic ketones with sulfonyl azides
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Ru(ii)-catalyzed intermolecular ortho-C-H amidation of weakly coordinating aromatic ketones with sulfonyl azides is reported. The developed reaction protocol can be extended to various substituted aromatic ketones to afford a wide range of desired C-N bond formation products in good yields.
- Bhanuchandra,Ramu Yadav,Rit, Raja K.,Rao Kuram, Malleswara,Sahoo, Akhila K.
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p. 5225 - 5227
(2013/06/27)
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- 1-(2′-Anilinyl)prop-2-yn-1-ol rearrangement for oxindole synthesis
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A synthetic method that relies on NIS (N-iodosuccinimide)-mediated cycloisomerization reactions of 1-(2′-anilinyl)prop-2-yn-1-ols to gem-3-(diiodomethyl)indolin-2-ones and 2-(iodomethylene)indolin-3-ones has been developed. The reactions were shown to be chemoselective, with secondary and tertiary alcoholic substrates exclusively giving the 3- and 2-oxindole products, respectively. In the case of the latter, the transformation features an unprecedented double 1,2-OH and 1,2-alkyl migration relay. Density functional theory (DFT) calculations based on proposed iodoaminocyclization species provide insight into this unique divergence in product selectivity. Copyright
- Kothandaraman, Prasath,Koh, Bing Qin,Limpanuparb, Taweetham,Hirao, Hajime,Chan, Philip Wai Hong
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p. 1978 - 1985
(2013/03/14)
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- Silver acetate catalyzed hydroamination of 1-(2-(sulfonylamino)phenyl)prop- 2-yn-1-ols to (Z)-2-methylene-1-sulfonylindolin-3-ols
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A method to prepare (Z)-2-methylene-1-sulfonylindolin-3-ols efficiently that relies on silver acetate catalyzed hydroamination of 1-(2-(sulfonylamino) phenyl)prop-2-yn-1-ols is reported. The reactions proceed rapidly at room temperature with catalyst loadings as low as 1 mol % under conditions that did not require the exclusion of air or moisture. The utility of this N-heterocyclic ring-forming strategy as a synthetic tool that makes use of unsaturated alcohols was exemplified by the conversion of the (Z)-2-methylene-1- sulfonylindolin-3-ol to examples of other members of the indole family of compounds.
- Susanti, Dewi,Koh, Fujiet,Kusuma, Jeffrey Antonius,Kothandaraman, Prasath,Chan, Philip Wai Hong
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p. 7166 - 7175
(2012/10/29)
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- Electrophile-driven regioselective synthesis of functionalized quinolines
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Highly substituted 3-iodoquinolines bearing different alkyl and aryl moieties can be synthesized in moderate to excellent yields (up to 99%) by 6-endo-dig iodocyclization of 2-tosylaminophenylprop-1-yn-3-ols with molecular iodine (I2) under mil
- Ali, Shaukat,Zhu, Hai-Tao,Xia, Xiao-Feng,Ji, Ke-Gong,Yang, Yan-Fang,Song, Xian-Rong,Liang, Yong-Min
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supporting information; experimental part
p. 2598 - 2601
(2011/06/26)
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- Cyclopropyl carbinol rearrangement for benzo-fused nitrogen ring synthesis
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A synthetic method that relies on gold-catalysed cyclopropyl carbinol rearrangement of 2-tosylaminophenyl cyclopropylmethanols to prepare 2,3-dihydro-1H-benzo[b]azepines and 2-vinylindolines efficiently is reported. The reactions were shown to be chemoselective, with secondary and tertiary alcohol substrates exclusively providing benzo-fused five- and seven-membered ring products, respectively. The ring-forming process was also found to proceed in moderate to excellent yields under mild conditions only in the presence of the gold and silver catalyst combination. The mechanism is thought to involve activation of the alcohol by the (p-CF3C6H 4)3PAuCl/AgOTf (Tf=triflate) catalyst, resulting in ionization of the starting material. The tertiary carbocationic intermediate generated in situ in this manner then triggers ring-opening of the cyclopropane moiety and trapping by the tethered aniline group to give the 2,3-dihydro-1H-benzo[b]azepine. Cyclopropane ring fragmentation of the secondary carbocationic analogue, on the other hand, results in diene formation followed by subsequent intramolecular hydroamination to afford the 2-vinylindoline. Copyright
- Kothandaraman, Prasath,Huang, Chuhui,Susanti, Dewi,Rao, Weidong,Chan, Philip Wai Hong
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supporting information; experimental part
p. 10081 - 10088
(2011/10/09)
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- Gold-catalyzed cycloisomerizations of 1-(2-(Tosylamino)phenyl)prop-2-yn-1- ols to 1H-Indole-2-carbaldehydes and (E)-2-(Iodomethylene)Indolin-3-ols
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A method to prepare lH-indole-2-carbaldehydes and (E)-2-(iodomethylene) indolin-3-ols by gold(I)-catalyzed cycloisomerization of l-(2-(tosylamino) phenyl)prop-2-yn-1-ols with N-iodosuccinimide (NIS) is reported. The reactions were shown to be operationally simplistic and proceed efficiently for a wide variety of substrates, affording the corresponding products in good to excellent yields (70-99%). The mechanism is suggested to involve activation of the alkyne moiety of the substrate by the gold(I) catalyst. This triggers intramolecular addition of the tethered aniline moiety to give a vinyl gold intermediate, which undergoes iododeauration with NIS to give the (E)-2-(iodomethylene)indolin-3-ol adduct. Subsequent 1,3-allylic alcohol isomerization (1,3-AAI) followed by formylation of this vinyl iodide intermediate then gives the 1H-indole-2-carbaldehyde.
- Kothandaraman, Prasath,Mothe, Srinivasa Reddy,Toh, Sharon Si Min,Chan, Philip Wai Hong
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experimental part
p. 7633 - 7640
(2011/11/12)
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- Gold-catalyzed cycloisomerization reactions of 2-tosylamino-phenylprop-1- yn-3-ols as a versatile approach for indole synthesis
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(Chemical equation presented) A great combination: A putative indolyl-substituted vinyl gold species generated in situ from AuCl/AgOTf catalyzed the title transformation. Under these reaction conditions, indenyl-fused and 2,3-disubstituted indole derivati
- Kothandaraman, Prasath,Rao, Weidong,Foo, Shi Jia,Chan, Philip Wai Hong
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supporting information; experimental part
p. 4619 - 4623
(2010/08/19)
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- Copper(II) triflate-catalyzed intramolecular hydroamination of homoallylic amino alcohols as an expedient route to trans-2,5-dihydro-1H-pyrroles and 1,2-dihydroquinolines
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A new efficient synthetic route to trans-2,5-dihydro-1H-pyrroles and 1,2-dihydroquinolines that relies on copper(II) triflate-catalyzed intramolecular hydroamination of homoallylic amino alcohols under mild and operationally straightforward conditions is
- Rao, Weidong,Kothandaraman, Prasath,Koh, Chii Boon,Chan, Philip Wai Hong
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supporting information; experimental part
p. 2521 - 2530
(2011/02/21)
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- Simple route to 3-(2-indolyl)-1-propanones via a furan recyclization reaction
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A simple route to 1-R-3-(2-indolyl)-1-propanones has been elaborated based on recyclization of 2-(2-aminobenzyl)furan derivatives. Being a modification of the Reissert indole synthesis, our approach employs the furan ring as a source of carbonyl function. This approach is general and allows varying of substituents in aromatic ring as well as in 3-position of indole nucleus.
- Butin, Alexander V.,Smirnov, Sergey K.,Stroganova, Tatyana A.,Bender, Wolfgang,Krapivin, Gennady D.
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p. 474 - 491
(2007/10/03)
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- Synthesis and biological evaluation of substituted 2-sulfonyl-phenyl-3-phenyl-indoles: A new series of selective COX-2 inhibitors
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A new series of substituted 2-sulfonyphenyl-3-phenyl-indole derivatives were synthesized and evaluated for their ability to inhibit COX-2 and COX-1enzymes. Most of the compounds synthesized were found to be highly potent and selective inhibitors of COX-2. This work led to the discovery of 2-aminosulfonylphenyl-3-phenyl-indole 5a which possesses higher activity and selectivity for COX-2 than Celecoxib both in vitro and in vivo.
- Hu, Wenhui,Guo, Zongru,Chu, Fengming,Bai, Aiping,Yi, Xiang,Cheng, Guifang,Li, Jing
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p. 1153 - 1160
(2007/10/03)
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