157019-58-4Relevant articles and documents
Transmission of substituent effects through extended systems-III. p-Substituted ethyl trans cinnamates and phenylpropiolates
Butt, G.,Topsom, R. D.
, p. 649 - 654 (1982)
Infrared data and 13C chemical shifts are reported for a series of ethyl p-substituted trans-cinnamates and ethyl phenylpropiolates.The i.r. values include intensities for the benzene, ethylene and carbonyl vibrations which allow an estimation of resonance effects.The relative importance of the various mechanisms of transmission of substituent effects are discussed and compared to those previously reported for p-substituted trans cinnamonitriles.It is shown that the carbon-carbon triple bond is less efficient in transmitting substituent effects than carbon-carbon double bonds.
Preparation method of neoflavonoids
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, (2017/04/26)
The invention relates to the field of chemical synthesis, in particular to a preparation method of neoflavonoids. The preparation method is characterized by comprising the following steps of using substituted benzaldehyde as an initial raw material to be reacted with malonic acid to generate a substituted phenylacrylic acid compound; performing an addition reaction, an elimination reaction and the like on the substituted phenylacrylic acid compound, or performing acetylation so as to protect a phenolic hydroxyl group, then performing a bromination reaction and the elimination reaction so as to synthesize the substituted phenylpropiolic acid compound ; and using montmorillonite K-10 after being acidulated by sulfuric acid as a catalyst, enabling the substituted phenylpropiolic acid compound and a phenolic compound to perform a heating reaction so as to generate the neoflavonoids. Compared with the prior art, the preparation method of the neoflavonoids, disclosed by the invention, has the characteristics that raw materials are cheap, and easy to obtain, the operation is simple, the catalyst can be recovered for use, and the method is environmentally-friendly, the post-treatment is simple, and the production cost is low, and the method has a high popularization and application value.
Enantioselective Catalytic Epoxidation of Cinnamate Esters
Jacobsen, Eric N.,Deng, Li,Furukawa, Yoshiro,Martinez, Luis E.
, p. 4323 - 4334 (2007/10/02)
A broad study of the (salen)Mn(III)-catalyzed asymmetric epoxidation of cis-cinnamate esters reveals that the steric properties of the ester group have a profound influence on enantioselectivity in the epoxidation reaction, with bulkier esters affording highest ee's.The sensitivity of the reaction selectivity to the steric properties of the cis-alkene are consistent with a "skewed" side-on approach of olefin to the metal -oxo.The electronic properties of the substrate arene ring substituents do not correlate with epoxidation ee, but instead with the cis/trans partitioning of product formation.Evidence is provided for a non-polar inter mediate in a stepwise oxygen-atom-transfer mechanism.The presence of pyridine N-oxide derivatives has a significant effect on catalysts rates and total turnovers, but negligible influence on the stereoselectivity of epoxidation.A mechanistic basis for the role of these additives is proposed.The synthetic applicability of the cinnamate epoxidation methodology is illustrated in the highly enantioslective synthesis of diltiazem.
