41122-67-2Relevant academic research and scientific papers
Double stereodifferentiation in the catalytic asymmetric aziridination of imines prepared from α-chiral amines
Huang, Li,Zhang, Yu,Staples, Richard J.,Huang, Rui H.,Wulff, William D.
supporting information; experimental part, p. 5302 - 5313 (2012/05/20)
The catalytic asymmetric aziridination of imines and diazo compounds (AZ reaction) mediated by boroxinate catalysts derived from the VANOL and VAPOL ligands was investigated with chiral imines derived from five different chiral, disubstituted, methyl amines. The strongest matched and mismatched reactions with the two enantiomers of the catalyst were noted with disubstituted methyl amines that had one aromatic and one aliphatic substituent. The synthetic scope for the AZ reaction was examined in detail for α-methylbenzyl amine for cis-aziridines from α-diazo esters and for trans-aziridines from α-diazo acetamides. Optically pure aziridines could be routinely obtained in good yields and with high diastereoselectivity and the minor diastereomer (if any) could be easily separated. The matched case for cis-aziridines involved the (R)-amine with the (S)-ligand, but curiously, for trans-aziridines the matched case involved the (R)-amine with the (R)-ligand for imines derived from benzaldehyde and n-butanal, and the (R)-amine with the (S)-ligand for imines derived from the bulkier aliphatic aldehydes pivaldehyde and cyclohexane carboxaldehyde.
Asymmetric organocatalytic efficiency of synthesized chiral β-amino alcohols in ring-opening of glycidol with phenols
Aral, Tarik,Karakaplan, Mehmet,Hosgoeren, Halil
experimental part, p. 794 - 802 (2012/08/28)
A series of novel chiral β-amino alcohols 3-5 and 7-10 were synthesized by regioselective ring opening of epoxides and chiral amines with a straightforward method in high yields (up to 99 %). Kinetic resolution of racemic glycidol with phenols was achieved by using chiral amino alcohols as organocatalysts. Amino alcohols 5, 8 and 10 exhibited the highest enantioselectivities with p-cresol, phenol, and p-methoxyphenol by 63, 65, 58 % ee, respectively. The moderate enantioselectivities were observed with catalyst 9b towards all the nucleophiles (34-48 % ee). The ee values of the desired 3-aryloxy-1, 2-diols were determined by HPLC. This study presents an attractive tool for the synthesis of β-blockers and structurally complex molecules.
Dynamic molecular propeller: Supramolecular chirality sensing by enhanced chiroptical response through the transmission of point chirality to mobile helicity
Katoono, Ryo,Kawai, Hidetoshi,Fujiwara, Kenshu,Suzuki, Takanori
supporting information; experimental part, p. 16896 - 16904 (2010/04/04)
The secondary terephthalamide host 1a-H attached to four aryl blades was prepared from tetrabromide 2a by Suzuki-Miyaura coupling and undergoes a conformational change from a nonpropeller anti-form to a propeller-shaped syn-form upon complexation with dit
Deracemization by enantioselective dehydrohalogenation. Synthesis of optically active compounds bearing a chiral axis.
Duhamel, L.,Ravard, A.,Plaquevent, J. C.,Ple, G.,Davoust, D.
, p. 787 - 797 (2007/10/02)
This work describes the deracemization of 4-tert-butyl and 4-methylcyclohexylidene acetic acids bearing a chiral axis.Enantioselective dehydrohalogenation of prochiral species by chiral lithium amides allowed us to obtain e.e. as high as 82percent.A mecha
