176504-88-4Relevant articles and documents
Organocatalytic ?±-addition of isocyanides to aldehydes
Yamada, Takeshi,Hirose, Tomoyasu,O??mura, Satoshi,Sunazuka, Toshiaki
supporting information, p. 296 - 301 (2015/03/04)
?±-Hydroxyamide is an important chemical component widely observed in biologically active natural products. One of the most direct methods to access a ?±-hydroxyamide is the Passerini-type reaction. However, this catalytic process was limited. Herein, we
Nucleophilic acyl substitutions of anhydrides with protic nucleophiles catalyzed by amphoteric, oxomolybdenum species
Chen, Chien-Tien,Kuo, Jen-Huang,Pawar, Vijay D.,Munot, Yogesh S.,Weng, Shieu-Shien,Ku, Cheng-Hsiu,Liu, Cheng-Yuan
, p. 1188 - 1197 (2007/10/03)
(Chemical Equation Presented) Among six different group VIb oxometallic species examined, dioxomolybdenum dichloride and oxomolybdenum tetrachloride were the most efficient catalysts to facilitate nucleophilic acyl substitution (NAS) of anhydrides with a myriad array of alcohols, amines, and thiols in high yields and high chemoselectivity. In contrast to the well-recognized redox chemical behaviors associated with oxomolybdenum(VI) species, the catalytic NAS was unprecedented and tolerates virtually all kinds of functional groups. By using benzoic anhydride as a mediator for in situ generation of an incipient mixed anhydride-MoO2Cl2 adduct with a given functional alkanoic acid, one can achieve oleate, dipeptide, diphenylmethyl, N-Fmoc-α-amino, pyruvic, and tert-butylthio ester, N-tert-butylamide, and trityl methacrylate syntheses with appropriate protic nucleophiles. The amphoteric character of the Mo=O unit in oxomolybdenum chlorides was found to be responsible for the catalytic NAS profile as supported by a control NAS reaction of using an authentic adduct-MoOCl2(O2-CBu t)2 between pivalic anhydride and MoO2Cl 2 as the catalyst.
Asymmetric syntheses of (R)- and (S)-2-aminobutanesulfonic acid and their 3,3-dimethylderivatives
Braghiroli, Daniela,Di Bella, Maria
, p. 2145 - 2150 (2007/10/03)
(R)- and (S)-2-aminobutanesulfonic acid, 3a and 3b, and (R)- and (S)-2-amino-3,3-dimethylbutanesulfonic acid, 4a and 4b, were synthesized from the corresponding N-Boc protected β-amino alcohols in good yields and high enantiomeric purities (> 99% ee).