80641-33-4Relevant academic research and scientific papers
Synthetic and mechanistic studies of metal-free transfer hydrogenations applying polarized olefins as hydrogen acceptors and amine borane adducts as hydrogen donors
Yang, Xianghua,Fox, Thomas,Berke, Heinz
experimental part, p. 852 - 860 (2012/02/05)
Metal-free transfer hydrogenation of polarized olefins (RR′ CCEE′: R, R′ = H or organyl, E, E′ = CN or CO2Me) using amine borane adducts RR′NH-BH3 (R = R′ = H, AB; R = Me, R′ = H, MAB; R = tBu, R′ = H, tBAB; R = R′ = Me, DMAB) as hydrogen donors, were studied by means of in situ NMR spectroscopy. Deuterium kinetic isotope effects and the traced hydroboration intermediate revealed that the double H transfer process occurred regio-specifically in two steps with hydride before proton transfer characteristics. Studies on substituent effects and Hammett correlation indicated that the rate determining step of the HN transfer is in agreement with a concerted transition state. The very reactive intermediate [NH2BH2] generated from AB was trapped by addition of cyclohexene into the reaction mixture forming Cy2BNH2. The final product borazine (BHNH)3 is assumed to be formed by dehydrocoupling of [NH2BH2] or its solvent stabilized derivative [NH2BH2]-(solvent), rather than by dehydrogenation of cyclotriborazane (BH2NH 2)3 which is the trimerization product of [NH 2BH2].
Nucleophilic Attacks on Carbon-Carbon Double Bonds. 28.1,2 Complete and Partial Stereoconversion in the Substitution of Methyl (E)- and (Z)-β-Chloro-α-cyano-p-nitrocinnamates by Nucleophiles
Rappoport, Zvi,Avramovitch, Bianca
, p. 1397 - 1408 (2007/10/02)
Methyl (E)- and (Z)-β-chloro-α-cyano-p-nitrocinnamates 5-E and 5-Z were prepared and separated.The stereochemistry of the substitution of the chlorine by nucleophiles was invastigated in MeCN, MeOH, or their mixtures.Reaction with p-toluenethiolate ion ga
