- Nitrogen fixation: Synthesis of heterocycles using molecular nitrogen as a nitrogen source
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Nitrogen fixation using transition metals is a fascinating process. We have already reported on the incorporation of molecular nitrogen into organic compounds using a titanium-nitrogen complex reported by Yamamoto. We developed a novel titanium-catalyzed nitrogenation procedure using TiCl4 in the presence of an excess amount of Li and TMSCl. In this reaction, a 1 atm pressure of nitrogen gas can be used and the reaction proceeds at room temperature. The procedure is very simple. A THF solution of TiCl4 or Ti(O iPr)4 (1 equiv.), Li (10 equiv.), and TMSCl (10 equiv.) was stirred under an atmosphere of nitrogen at room temperature overnight to give titanium-nitrogen complexes. Although the structures of the titanium-nitrogen complexes have not yet been determined, they would consist of N(TMS)3, X2TiN(TMS)2, and XTi=NTMS. Using this procedure, various heterocycles, such as indole, quinoline, pyrrole, pyrrolizine, and indolizine derivatives, could be synthesized from molecular nitrogen in good-to-moderate yields as a stoichiometric reaction based on a titanium complex by a one-pot reaction. Furthermore, monomorine I and pumiliotoxin C were synthesized from molecular nitrogen as a nitrogen source. This procedure was further extended for the syntheses of heterocycles using a catalytic amount of titanium complex; also, indole and pyrrole derivatives were obtained in high yields.
- Mori, Miwako,Akashi, Masaya,Hori, Masanori,Hori, Katsutoshi,Nishida, Mayumi,Sato, Yoshihiro
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p. 1655 - 1670
(2007/10/03)
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- RECYCLIZATION OF 2-(2-ACYLETHYL)PYRIDINIUM SALTS
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Recyclization of 2-(2-acylethyl)pyridinium salts on treatment with nucleophiles may occur in different ways, to give heterocyclic compounds of various classes, namely indoles (the Kost-Sagitullin reaction products), 4-aminoindoles, and 3-hydroxy-1,2,3,4-tetrahydroquinolines, the formation of which constitute novel reactions in the recyclization of pyridinium salts.
- Terenin, V. I.,Rumyantsev, A. N.,Nosyrev, P. V.,Gromov, S. P.,Bundel', Yu. G.
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p. 1016 - 1022
(2007/10/02)
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- THE SYNTHESIS AND CHEMISTRY OF AZOLENINES. PART 8. THE PAAL-KNORR REACTION WITH CYCLIC 2-(ACYLMETHYL)-2-ALKYL-1,3-DIKETONES: ISOLATION OF 1-ACYL-1H-PYRROLES VIA REARRANGEMENT
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Treatment of cyclic 2-acylmethyl-2-alkyl-1,3-diketones with ammonium acetate under reflux in acetic acid gives moderate to high yields of 1-acyl-1H-pyrroles by rearrangement.Some of the cyclic diketones react quantitatively with liquid ammonia to yield 2-
- Maini, Prem Nath,Sammes, Michael P.,Katritzky, Alan R.
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p. 161 - 168
(2007/10/02)
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- Synthesis and Mass Spectrometry of 4-Oxo-4,5,6,7-tetrahydroindole and 4-Oxo-4,5,6,7-tetrahydrobenzofuran Derivatives
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We describe in this communication the synthesis and mass spectrometry of some 1-aryl-2-phenyl-4-oxo-4,5,6,7-tetrahydroindole (IIIb, IVab-VIIab,VIIIb, IXb) and 2-phenyl-4-oxo-4,5,6,7-tetrahydrobenzofuran derivatives (IIab).The fragmentations of these compo
- Dagher, C.,Hanna, R.,Terentiev, P. B.,Boundel, Y. G.,Kost, A. N.,Maksimov, B. I.
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p. 645 - 647
(2007/10/02)
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