- Halogen Bond Catalyzed Bromocarbocyclization
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A halogen bond catalyzed bromo-carbocyclization of N-cinnamyl sulfonamides and O-cinnamyl phenyl ethers has been developed. N-methyl 4-iodopyridinium triflate is used as the halogen-bonding organocatalyst and the reaction is highly chemoselective. This report represents the first proof-of-concept for halogen-bonding organocatalyst-promoted electrophilic halogenation. Mechanistic study suggests the autocatalytic nature of this reaction.
- Chan, Yuk-Cheung,Yeung, Ying-Yeung
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supporting information
p. 3483 - 3487
(2018/02/28)
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- Palladium-catalyzed intramolecular oxidative coupling involving double C(sp2)-H bonds for the synthesis of annulated biaryl sultams
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The palladium-catalyzed intramolecular oxidative coupling described herein involves a double C(sp2)-H bond functionalization in sulfonanilides, providing a workable access to biaryl sultams annulated into a six-membered ring that are otherwise difficult to obtain by literature methods. The other synthetic applications of this protocol including the synthesis of biaryl sultams containing a seven-membered ring and analogous sultones are also presented.
- Laha, Joydev K.,Jethava, Krupal P.,Dayal, Neetu
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p. 8010 - 8019
(2015/03/18)
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- Palladium-catalyzed regiocontrolled domino synthesis of N-sulfonyl dihydrophenanthridines and dihydrodibenzo[c, e]azepines: Control over the formation of biaryl sultams in the intramolecular direct arylation
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A palladium-catalyzed domino N-benzylation/intramolecular direct arylation involving sulfonanilides and 2-bromobenzyl bromides has been developed for the first time, providing a workable access to N-sulfonyl dihydrophenanthridines in good to excellent yields. Under the optimized conditions, the formation of 5,6-dihydrophenanthridines was largely controlled over the formation of biaryl sultams containing a seven member ring. The optimized condition was found extendable to the regiocontrolled domino formation of N-sulfonyl-6,7-dihydro-5H-dibenzo[c,e]azepines over the biaryl sultam formation. Using an appropriate substrate, a biaryl sultam has been obtained exclusively.
- Laha, Joydev K.,Dayal, Neetu,Jain, Roli,Patel, Ketul
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p. 10899 - 10907
(2015/01/08)
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- Base-free monosulfonylation of amines using tosyl or mesyl chloride in water
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A mild and efficient procedure has been developed for the monosulfonylation of various amines using mesyl or tosyl chlorides in water at room temperature to afford the corresponding sulfonamides in high yields.
- Kamal, Ahmed,Reddy, J. Surendranadha,Bharathi, E. Vijaya,Dastagiri
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p. 348 - 353
(2008/09/17)
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- Intramolecular reactions of alkynes with furans and electron rich arenes catalyzed by PtCl2: The role of platinum carbenes as intermediates
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5-(2-Furyl)-1-alkynes react, with PtCl2 as catalyst, to give phenols. On the basis of DFT calculations, a cyclopropyl platinacarbene complex was found as the key intermediate in the process. The cyclopropane and dihydrofuran rings of this intermediate open to form a carbonyl compound, which reacts with the platinum carbene to form an oxepin, which is in equilibrium with an arene oxide. When the reaction is carried out in the presence of water, dicarbonyl compounds are obtained, which support the proposed mechanism. Other cyclizations of alkynes with furans or electron-rich arenes give products of apparent Friedel-Crafts-type reactions, although these processes could also proceed by pathways involving the formation of cyclopropyl platinum carbenes.
- Martin-Matute, Belen,Nevado, Cristina,Cardenas, Diego J.,Echavarren, Antonio M.
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p. 5757 - 5766
(2007/10/03)
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- Synthesis of 8,9,10-Trimethoxyellipticine
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4,5,6-Trimethoxyindole was synthesised by three independent routes and condensed with hexane-2,5-dione to give 1,4-dimethyl-5,6,7-trimethoxycarbazole.Formylation of the latter gave a mixture including the 3-formyl derivative which was converted into 8,9,1
- Hewlins, Michael J. E.,Jackson, Anthony H.,Oliveira-Campos Ana-M.,Shannon, Patrick V. R.
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p. 2906 - 2911
(2007/10/02)
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