78141-07-8Relevant academic research and scientific papers
Titanium enolates and "ate" complexes of N,N-disubstituted amides and thioamides in the Michael reaction
Viteva, Lilia Z.,Gospodova, Tzveta S.,Stefanovsky, Yuri N.
, p. 7193 - 7202 (2007/10/02)
The synthetic potential, regio- and stereoselectivity of titanium dialkylamide and dialkylthioamide enolates and "ate" complexes in reaction with some conjugate carbonyl compounds are investigated. Titanium enolates react preferentially in 1,2-position while "ate" complexes afford 1,4-regiocontrol. The stereochemical behaviour of the latter follows in general the lithium and potassium precursors. Marked influence of solvent and of electrophile geometry on 1,4-stereoselectivity was found with the amides but not with the thioanalogs. The stereochemistry of the amide titanium "ate" complexes is correlated with a cyclic transition state. The solvent effect is explained by involvement into the transition structure. Some advantages of the titanium "ate" complexes are discussed.
MICHAEL ADDITION OF PHENYLACETIC ACID DIALKYLAMIDE AND ESTER ENOLATES TO Z-METHYL CINNAMATE. DEPENDENCE OF THE STEREOCHEMISTRY ON THE ACCEPTOR GEOMETRY.
Viteva, Lilia,Stefanovsky, Yuri
, p. 5649 - 5652 (2007/10/02)
The dependence of the stereochemical course on the acceptor geometry and on the metal counterion is demonstrated in the kinetic Michael addition of phenylacetic acid dialkylamide and ester enolates to Z-methyl cinnamate.The results obtained are consistent with cyclic transition state models.
Michael Reaction. IV. NaNH2 Catalyzed One Stage Reaction Between Phenylacetic Acid Dialkylamides and Cinnamic Acid Methyl Ester or Dialkylamides. Influence of Reaction Conditions on the Stereochemistry
Stefanovsky, Yuri N.,Viteva, Lilia Z.
, p. 1287 - 1298 (2007/10/02)
The NaNH2 catalyzed one stage reaction between phenylacetic acid dialkylamides and cinnamic acid methyl ester or dialkylamides was studied under various conditions.Conditions were found for easy preparation of each of the both possible diastereomeric deri
