78019-43-9Relevant academic research and scientific papers
Regio-, Stereo-, and Enantioselectivity in the Electrophilic Reactions of 2-Amino-4-phenyl-3-butenenitriles
Chang, Chih-Jung,Fang, Jim-Min,Liao, Li-Fan
, p. 1754 - 1761 (2007/10/02)
The allylic anion generated from 2-(N-methylanilino)-4-phenyl-3-butenenitrile (1) reacted with iodomethane and 3-bromo-1-chloropropane in THF/HMPA to give γ-substituted products exclusively, predominantly in the 2Z-configuration.Substitution of the N-methylanilino group with the methyl ether of L-(-)-ephedrine resulted in the generation of chiral aminonitrile 2.Lithiated 2 reacted sluggishly in THF with allyl bromide and benzyl chloride in the absence of HMPA to give the γ-substituted products predominantly in the 2Z-configuration, with little diastereoselectivity.The aminonitrile 3 prepared from cinnamaldehyde, L-(-)-ephedrine, and KCN was lithiated with 2 equiv of LDA resulting in high facial selectivity (76 - 100 percent diastereomeric excess) in alkylations in the presence of HMPA and LiI.Lithiated 3 reacted with propionaldehyde, benzaldehyde, and p-bromobenzaldehyde at -78 deg C to give the γ-addition products, predominantly in the 4R-configuration (64 -78 percent de).The stereochemistry of the isomers of each product was determined by chemical correlation and spectral methods including analyses of the CD spectra and X-ray diffraction.A bicyclic transition state C wherein lithium is chelated by both amino and alkoxy groups is proposed to interpret the observed stereoselectivity.
Metal Catalysis in Organic Reactions. 12. Asymmetric Induction Phenomena in the Isomerization of Racemic 1-Alkenes by Chiral Aluminum Solvate-Nickel Systems
Giacomelli, Giampaolo,Bertero, Luigi,Lardicci, Luciano,Menicagli, Rita
, p. 3707 - 3711 (2007/10/02)
The isomerization of some racemic 1-alkenes in the presence of chiral amine-triisobutylaluminum solvate-bis(N-methylsalicylaldimine)nickel systems has been studied.The susceptibility to isomerization of the alkenes was found to be related to their structu
