- Reaction of four-membered cyclic nitrones with acetyl chloride. X-Ray crystal structures of 2--N,N-diethyl-2-methyl-4-oxo-3-phenylpentanamide and 1-acetyl-3-chloro-N,N-diethyl-2-methyl-4-methylene-3-phenyl-2-azetidinecarboxamide
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Reactions of the four-membered cyclic nitrones 1 with acetyl chloride differ strongly from those of other (cyclic) nitrones.In the presence of water, the nitrones 1 yield the 2--N,N-diethylalkanamides 4.The structure of 4b was confirmed by X-ray analysis.In the absence of water, the N,N-diethyl-4-methylene-2-azetidinecarboxamides 5 or the N,N-diethyl-2,3-dihydro-2-azetecarboxamides 6 were obtained.X-ray analysis elucidated the structure of 5a.Under acidic conditions, compound 5a yielded the 2-oxa-5-azabicyclohexan-3-one derivative 13.Acid hydrolysis of 6a gave the α-chloroketone derivative 18 and the 2-oxopropanamide derivative 19.
- Eijk, Peter J. S. S. van,Trompenaars, Willem P.,Reinhoudt, David N.,Harkema, Sybolt
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- Chemistry of diamino-ligated methylpalladium(II) alkoxides and aryloxides (Part II): Methoxide formation and carbonylation reactions
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Reaction of N-ligated methylpalladium(II) alkoxide and aryloxide complexes [Pd(Me)(OR)(N ~ N)] (R = Ph, CH(CF3)2; N ~ N = tmeda (N,N,N′,N′-tetramethylethylenediamine) or bpy (2,2′-bipyridyl)) with carbon monoxide produces the corresponding methylesters in high yields. The insertion takes place either into the Pd-Me bond (aryloxide complexes) or into the Pd-OR bond (alkoxide complexes). Methylpalladium(II) methoxide complexes [Pd(Me)(OMe)(N ~ N)] (N ~ N = tmeda, bpy) have been generated in situ by aryloxide- or alkoxide-methanol exchange reactions for which the equilibrium constants have been determined. The bpy-ligated methylpalladium methoxide complex undergoes insertion of CO producing either a methylpalladium methoxycarbonyl complex [Pd(Me)(CO2Me)(bpy)] (at -60°C) or an acylpalladium methoxycarbonyl complex [Pd(COMe)(CO2Me)(bpy)] (at -25°C); both carbonylated species could be isolated and characterized at low temperature.
- Kapteijn, Gerardus M.,Dervisi, Athanasia,Verhoef, Michel J.,Van Den Broek, M.A. Frederik H.,Grove, David M.,Van Koten, Gerard
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p. 123 - 131
(2007/10/03)
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- Iron-catalysed Oxidation of N,N-(Dialkyl)acylmethylamines with Molecular Oxygen in the Presence of either 2-Mercaptoethanol or Sodium Sulphide
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Air-oxidation of N,N-(dialkyl)acylmethylamines (1a-f) using a catalytic amount of 2O> in the presence of 2-mercaptoethanol gave the corresponding α-oxo amides (2a-f) in moderate to good yields.With sodium sulphide in place of the thiol α-oxo thioamides (9a-f) were obtained as the predominant products.
- Murata, Satoru,Suzuki, Kaoru,Miura, Masahiro,Nomura, Masakatsu
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p. 361 - 365
(2007/10/02)
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- Preparation of trans-Pd(COCOR)Cl(PMePh2)2 complexes (R = Ph and Me) and their reactivities related to double carbonylation promoted by palladium
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In order to examine the feasibility of the reaction mechanism involving double insertion of CO into the Pd-C bond in the double carbonylation of organic halides catalyzed by palladium complexes giving α-keto amides, trans-Pd(COCOR)Cl(PMePh2)2 complexes (R = Me, 3a; Ph, 3b) were prepared, and their reactivities with Et2NH were investigated. Complexes 3a and 3b were prepared by the reactions of Pd(styrene)(PMePh2)2 with the corresponding RCOCOCl and were characterized by means of IR and NMR spectroscopy and elemental analysis. Complexes 3a and 3b undergo a facile decarbonylation in solution obeying the first-order rate law with respect to the concentration of the palladium complexes to give quantitative yields of acyl complexes, trans-Pd(COR)Cl(PMePh2)2. The decarbonylation reactions are effectively retarded by the addition of free PMePh2, suggesting a reaction mechanism involving a rate-determining dissociation of tertiary phosphine ligand. Treatment of 3a with Et2NH gives MeCONEt2 as the major product. This result is in sharp contrast with the reaction of the corresponding acyl complex, trans-Pd(COMe)Cl(PMePh2)2, with Et2NH under CO atmosphere, where MeCOCONEt2 was obtained as the major product. These observations provide the evidence against the mechanism involving consecutive insertion of CO into the Pd-C bond.
- Ozawa, Fumiyuki,Sugimoto, Takeshi,Yamamoto, Takakazu,Yamamoto, Akio
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p. 692 - 697
(2008/10/08)
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- DOUBLE CARBONYLATION REACTIONS OF METHYL- AND PHENYLPALLADIUM(II) COMPLEXES IN THE PRESENCE OF SECONDARY AMINES AFFORDING α-KETO AMIDES
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The reactions of trans-PdR(X) (PMePh2)2 (R = Me, X = I and R = Ph, X = Br) with carbon monoxide in the presence of secondary amines, R'2NH, were found to give α-keto amides, RCOCONR'2, as double carbonylation products under mild conditions in good yields and selectivities.
- Ozawa, Fumiyuki,Yamamoto, Akio
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p. 865 - 868
(2007/10/02)
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