- One-Pot Generation of Benzynes from Phenols: Formation of Primary Anilines by the Deoxyamination of Phenols
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Benzynes were selectively generated in situ from phenols and trapped regioselectively with potassium hexamethyldisilazide to form primary anilines following acidic workup. The direct conversion of a phenolic hydroxyl group into a free amino group is a useful method for the preparation of primary aryl amines that are hard to synthesize by using coupling reactions involving phenol derivatives with ammonia. Whereas reactions of ortho- and meta-substituted phenols produced meta-substituted anilines exclusively, those of para-substituted phenols provided ortho-silylanilines.
- Akai, Shuji,Ikawa, Takashi,Masuda, Shigeaki
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- Total synthesis of nigellicine and nigeglanine hydrobromide
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(Chemical Equation Presented) The first syntheses of the pyridazinoindazolium alkaloids nigellicine and nigeglanine hydrobromide via a common intermediate are described. Ortho-lithiation/acylation and the direct amination of an isatin ring system are the
- Elliott, Eric L.,Bushell, Simon M.,Cavero, Marta,Tolan, Brian,Kelly, T. Ross
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p. 2449 - 2451
(2007/10/03)
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- The Kinetics of the Reactions of Picryl Chloride with Some Substituted Anilines. Part 5.
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Arrhenius parameters have been measured for the reactions of picryl chloride with the following substituted anilines in acetonitrile: 3-amino- and 3-methyl-aniline, 3-amino-5-nitroaniline, 3-fluoro-5-methylsulphonylaniline, 3-X-5-methylanilines (X=NO2, OMe, CH3, F, Cl, Br, or I) and 3,5-X2-anilines (X = F, Cl, Br, or I).A total of 33 3,5-disubstituted anilines have now been examined for the additivity of substituent effects on the free energy of activation, and it has been shown that with the exception of 3-amino-5-nitroaniline this hypothesis reproduces experimental rate constants within a factor of 2.A rationalization is proposed for the deviations that occur in some cases when more stringent criteria of additivity are used.
- Emokpae, Thomas A.,Eguavoen, Osa,Hirst, Jack
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p. 829 - 831
(2007/10/02)
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