- A [5 + 1] annulation strategy for the synthesis of multifunctional biaryls and: P -teraryls from 1,6-Michael acceptor ketene dithioacetals
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A new type of ketene dithioacetal, 2-(3,3-bis-methylsulfanyl-1-arylallylidene)malononitriles containing 1,4 and 1,6-Michael acceptors, were synthesized to study their reactivity for the synthesis of a new molecular entity. We report a [5 + 1] annulation s
- Althagafi, Ismail,Elagamy, Amr,Kumar, Abhinav,Pratap, Ramendra,Shally,Shaw, Ranjay
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p. 6407 - 6417
(2020/09/07)
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- NMR studies on intramolecular mobility of ortho-substituted push-pull phenyl butadienes
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The 1H and 13C NMR spectra of a series of 3-aryl-2-cyano-5,5-bis(methylthio)penta-2,4-dienenitriles (3) and 3-aryl-2-cyano-5-dimethylamino-5-methylthiopenta-2,4-dienenitriles (4) with different ortho-phenyl substituents were recorded. The NMR data are compared with those of the corresponding para-substituted compounds 1 and 2. Dynamic 1H NMR measurements showed rotation processes about the C-2,C-3, C-3,C-4, C-4,C-5, and C-5,N bonds. The free energies of activation ΔG?c are discussed with respect to electronic and steric effects of the substituents. The magnitude of the rotation barriers correlates with the variation in bond lengths and angles as determined by X-ray structure analyses.
- Freier, Thomas,Michalik, Manfred,Peseke, Klaus,Reinke, Helmut
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p. 1265 - 1271
(2007/10/03)
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