- Synthesis of nitrogenated heterocycles by asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)haloimines
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Highly optically enriched, protected, nitrogenated heterocycles with different ring sizes have been synthesized by a very efficient methodology consisting of the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl) haloimines followed by treatment with a base to promote an intramolecular nucleophilic substitution process. N-Protected aziridines, pyrrolidines, piperidines, and azepanes bearing aromatic, heteroaromatic, and aliphatic substituents have been obtained in very high yields and diastereomeric ratios up to >99:1. The free heterocycles can be easily obtained by a simple and mild desulfinylation procedure. Both enantiomers of the free heterocycles can be prepared with the same good results by changing the absolute configuration of the sulfur atom of the sulfinyl group.
- Pablo, Oscar,Guijarro, David,Yus, Miguel
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p. 9181 - 9189
(2013/10/08)
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- Acylation of Grignard reagents mediated by N-methylpyrrolidone: A remarkable selectivity for the synthesis of ketones
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An efficient user-friendly method of acylation of Grignard reagents to selectively synthesize ketones is presented, which is assisted by simple amides such as NMP, or DMF. The present chemoselective method tolerates a variety of functional groups such as ketone, ester, nitrile and other functional groups.
- Gowda, Maravanhalli Sidde,Pande, Sushanth Sudhir,Ramakrishna, Ramesha Andagar,Prabhu, Kandikere Ramaiah
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supporting information; experimental part
p. 5365 - 5368
(2011/09/13)
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- Pyrazole-based sulfonamide and sulfamides as potent inhibitors of mammalian 15-lipoxygenase
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A series of inhibitors of mammalian 15-lipoxygenase (15-LO) based on a 3,4,5-tri-substituted pyrazole scaffold is described. Replacement of a sulfonamide functionality in the lead series with a sulfamide group resulted in improved physicochemical properties generating analogs with enhanced inhibition in cell-based and whole blood assays.
- Ngu, Khehyong,Weinstein, David S.,Liu, Wen,Langevine, Charles,Combs, Donald W.,Zhuang, Shaobin,Chen, Xing,Madsen, Cort S.,Harper, Timothy W.,Ahmad, Saleem,Robl, Jeffrey A.
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scheme or table
p. 4141 - 4145
(2011/08/06)
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- One-step preparation of α-chlorostyrenes
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α-Chlorostyrenes were prepared via a one-step method involving Friedel-Crafts reaction of various aromatic substrates with acid chlorides in the presence of a heterogeneous Si-Fe catalyst.
- Borate, Hanumant B.,Gaikwad, Abaji G.,Maujan, Suleman R.,Sawargave, Sangmeshwer P.,Kalal, Kamalakar M.
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p. 4869 - 4872
(2008/02/05)
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- MODERN FRIEDEL-CRAFTS CHEMISTRY XVI. REACTION OF THIOPHENE WITH BIFUNCTIONAL MOLECULES UNDER DIFFERENT FRIEDEL-CRAFTS CATALYSTS: ATTEMPTED SYNTHESIS OF CYCLOPENTA THIOPHENES AND DIHYDROBENZO THIOPHENES
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The reaction of thiophene (1) with 3-chloropropionyl chloride (2), 4-chlorobutyryl chloride (3), crotonyl chloride (4) and cinnamoyl chloride (5) under different Friedel-Crafts catalysts (AlCl3/CH3NO2, FeCl3, and AlCl3/CS2) was investigated.The cyclic products 4,5-dihydro-6H-4-methylcyclopenta-thiophen-6-one, 5,6-dihydrobenzothiophen-7(4H)one and 4-phenyl-6H-cyclopentathiophen-6-one were formed.The different behaviors of compounds (2-5) towards thiophene were discussed.
- El-Khagawa, Ahmed M.,El-Zohry, Maher F.,Ismail, Mohamed T.
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