- Theoretical, structural, vibrational, NMR, and thermal evidence of the inter- versus intramolecular hydrogen bonding in oxamides and thiooxamides
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This contribution describes the study of hydrogen bonding in secondary oxamides, monothiooxamides, and dithiooxamides by ab initio calculations, X-ray diffractions, NMR spectra, thermal analysis, and variable-temperature infrared and Raman spectroscopy. The results can all be interpreted as a function of the change in the strength and the nature of the hydrogen bonding by substituting oxygen for sulfur in the series CH3-HNCOCONHCH3, CH 3HNCSCONHCH3, CH3HNCSCSNHCH3 and by changing the steric influence of the alkyl group in a series of oxamides (RHNCOCNHR; R = CH3, C2H5, iC3H 7, tC49).
- Desseyn,Perlepes,Clou,Blaton,Van Der Veken,Dommisse,Hansen
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p. 5175 - 5182
(2007/10/03)
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- Oxidative coupling of amines and carbon monoxide catalyzed by palladium complexes. Mono- and double carbonylation reactions promoted by iodine compounds.
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Iodine is an effective promoter for the carbonylation of primary and secondary amines to ureas using palladium acetate as the catalyst and a base (e.g.K2CO3) in acetonitrile (3 h at 95 deg C and 2.7 atm).Oxamides are formed in excellent yields when secondary amines are carbonylated in the presence of iodide ion and oxygen, while primary amines give ureas as the principal product at 95 deg C, and oxamide at room temperature.
- Pri-Bar, Ilan,Alper, Howard
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p. 1544 - 1547
(2007/10/02)
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- Reactions of Tetrafluoroethylene Oligomers. Part 9. Some Reactions of Perfluoro(1-ethyl-1-methylpropyl)(s-butyl)ethanolide (an α-Lactone)
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The ethanolide (1), prepared by hypochlorite-mediated epoxidation of the ketene CF3(C2F5)2CC=C=O (2), decomposed when warmed at 90 deg C for 30 min to give the ketone CF3(C2F5)2CCOCF(CF3)C2F5 (3).Reaction of compound (1) with either triethylamine or trimethylamine afforded the olefin (E/Z)-CF3(C2F5)2CCH=C(CF3)C2F5 (4).Treatment of compound (1) with secondary amines R2NH (R=Et, R25) or primary amines RNH2 (R=c-C6H11 or But) afforded oxo amides of the type CF3(C2F5)CFCOCONR2 (5) and (6) and CF3(C2F5)CFCOCONHR (7) and (8).With ethylamine and isopropylamine the isolated products were the corresponding oxamides and the olefin (4).With sodium methoxide three products were formed, a trace of olefin (4), 2,4-dimethoxyperfluoro-3-methylpent-2-ene (10), and the oxo ester CF3(C2F5)CFCOCO2Me (11).Sodium ethoxide yielded the olefin (4), the oxo ester CF3(C2F5)CFCOCO2Et (12), and the olefin CF3CF=C(CF3)CF(CF3)OEt (13).Reaction of compound (1) with methylmagnesium iodide and ethylmagnesium iodide afforded the esters C2F5(CF3)C=C(CO2Me)C(Me)(CF3)C2F5 (14) and C2F5(CF3)C=C(CO2Et)C(Et)(CF3)C2F5 (15) respectively.Treatment of compound (1) with methyl-lithium gave a mixture of two products, the esters (14) and C2F5(CF3)(Me)CC(CO2Me)=C(Me)CF3 (16), by what appears to be an unusual attack on the ring oxygen.Reaction of compound (1) with ethanethiol gave the ester C2F5(CF3)CFCOCOSEt (17) and the olefin C2F5(CF3)C=C(CF3)SEt (18).Compound (1) on reaction with ammonia gave oxamide and the unusual cyanodi-imine CF3C(=NH)CH(CN)C(=NH)CF3 (9).Reaction of compound (1) with tributyl- or triphenyl-phosphine gave olefin (4) again by reaction on the ring oxygen.
- Coe, Paul L.,Owen, Ian R.,Sellars, Alan
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p. 1097 - 1103
(2007/10/02)
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