4894-25-1Relevant academic research and scientific papers
Asymmetric reduction of racemic 2-isoxazolines
Tokizane, Masashi,Sato, Kaori,Ohta, Tetsuo,Ito, Yoshihiko
experimental part, p. 2519 - 2528 (2009/04/04)
The kinetic resolution of racemic 2-isoxazolines was carried out by asymmetric reduction using borane with 1,2-amino alcohols as a chiral source. Using excess BH3-THF in the presence of (-)-norephedrine, optically active 1,3-amino alcohol derivatives were obtained with good ee but in lower yield, while the optically active substrates 2-isoxazolines were recovered with modest ee. The asymmetric reduction using 2.0 equiv of BH3-SMe2 was investigated as an alternative strategy for the synthesis of optically active products. After reduction, treatment of the resulting mixture with Et3N was successful in providing optically active isoxazolidine derivatives in good yields and with good ee. The choice of chiral source was also shown to have a significant effect. In particular, the use of (S)-α,α-diphenyl-2-pyrrolidinemethanol reversed the enantioselectivity of the recovered substrates.
Reaction of Hydroximic Chlorides with Hexabutylditin. A Mild Method for Generation and Cycloaddition of Nitrile Oxides.
Kim, Byeang Hyean
, p. 1199 - 1206 (2007/10/02)
A new method for the in situ generation of nitrile oxides is reported.The reaction conditions are mild and neutral.
Acid-Catalyzed Nitronate Cycloaddition Reactions. Useful Syntheses and Simple Transformations of 3-Acyl- and 3-Alkenylisoxazolines
Wade, Peter A.,Amin, Nayan V.,Yen, Hwa-Kwo,Price, David T.,Huhn, George F.
, p. 4595 - 4601 (2007/10/02)
Nitronic esters derived from primary nitro ketones, ethyl nitroacetate, and (phenylsulfonyl)nitromethane react with dipolarophiles in the presence of nonaqueous protic and Lewis acids to give nitrile oxide cycloadducts. α-Nitro ketones, ethyl nitroacetate
FRAGMENTATION OF NITRILE OXIDES WITH TRIETHYLAMINE
Caramella, P.,Corsaro, A.,Compagnini, A.,Albini, Marinone F.
, p. 4377 - 4380 (2007/10/02)
The formation of 1,2,4-oxadiazoles is frequently observed as a side reaction in cyclo additions with nitrile oxides generated in situ and follows from a fragmentation induced by Et3N.This latter is oxidized to N,N-diethylvinylamine, which is trapped as a cycloadduct.
Benzenesulfonylcarbonitrile Oxide. 4. Substitution Reactions of 3-(Phenylsulfonyl)isoxazolines
Wade, P. A.,Yen, H.-K.,Hardinger, S. A.,Pillay, M. K.,Amin, N. V.,et al.
, p. 1796 - 1800 (2007/10/02)
3-(Phenylsulfonyl)isoxazolines, readily obtained from alkenes by cycloaddition with benzenesulfonylcarbonitrile oxide, undergo a variety of substitution reactions.Alkyl, aryl, and acetylenic lithium reagents, cyanide, lithium or sodium alkoxides, and sodi
