623575-45-1Relevant academic research and scientific papers
Diastereoselectivities in Reductions of α-Alkoxy Ketones Are Not Always Correlated to Chelation-Induced Rate Acceleration
Bartolo, Nicole D.,Hornstein, Alana L.,Zhao, Annie Y.,Woerpel
, p. 296 - 302 (2019)
The chelation-control model is used to predict stereochemical outcomes of many organometallic reactions. Diastereoselectivity arises due to reaction with a chelated intermediate with sterically differentiated faces. Earlier studies with dimethylmagnesium
Asymmetric hydrogenation of aromatic ketones catalyzed by the TolBINAP/DMAPEN-ruthenium(II) complex: A significant effect of N-substituents of chiral 1,2-diamine ligands on enantioselectivity
Ooka, Hirohito,Arai, Noriyoshi,Azuma, Keita,Kurono, Nobuhito,Ohkuma, Takeshi
supporting information; experimental part, p. 9084 - 9093 (2009/04/11)
(Chemical Equation Presented) Asymmetric hydrogenation of acetophenone in the presence of Ru(II) catalysts coordinated by TolBINAP and a series of chiral 1,2-diamines was studied. The sense and degree of enantioselectivity were highly dependent on the N-substituents of the diamine ligands. The N-substituent effect was discussed in detail. Among these catalysts, the (S)-TolBINAP/(R)- DMAPEN-Ru(II) complex showed the highest enantioselectivity. The mode of enantioface selection was interpreted by using transition state models based on the X-ray structure of the catalyst precursor. The chiral catalyst effected the hydrogenation of alkyl aryl ketones and arylglyoxal dialkyl acetals to afford the chiral alcohol in >99% ee in the best cases. Hydrogenation of racemic benzoin methyl ether with the chiral catalyst through dynamic kinetic resolution gave the anti-alcohol (syn:anti = 3:97) in 98% ee, while the reaction of α-amidopropiophenones resulted in the syn-alcohols (symanti = 96:4 to >99:1) in >98% ee.
