937371-83-0Relevant articles and documents
Enantioselective reduction of ketoxime ethers with borane-oxazaborolidines and synthesis of the key intermediate leading to (S)-rivastigmine
Pakulski, Marcin M.,Mahato, Sanjit K.,Bosiak, Mariusz J.,Krzeminski, Marek P.,Zaidlewicz, Marek
, p. 716 - 721 (2012/09/21)
The reduction of representative alkyl aryl (E)-ketoxime O-benzyl ethers with borane catalyzed by terpene oxazaborolidines, derived from (1R)-nopinone and (1R)-camphor, gave the corresponding amines with 82-99% ee. Oxazaborolidines derived from (1S)-2-carene and (1S)-3-carene were less selective. (S)-1-(3-Methoxyphenyl)ethanamine (94% ee) the key intermediate in the synthesis of (S)-rivastigmine, was obtained by the reduction of (E)-1-(3-methoxyphenyl) ethanone O-benzyl oxime with borane/oxazaborolidine generated from (S)-valinol.
Asymmetric synthesis of primary amines via the spiroborate-catalyzed borane reduction of oxime ethers
Huang, Xiaogen,Ortiz-Marciales, Margarita,Huang, Kun,Stepanenko, Viatcheslav,Merced, Francisco G.,Ayala, Angel M.,Correa, Wildeliz,De Jesus, Melvin
, p. 1793 - 1795 (2008/02/02)
The enantioselective borane reduction of O-benzyloxime ethers to primary amines was studied under catalytic conditions using the spiroborate esters 5-10 derived from nonracemic 1,2-amino alcohols and ethylene glycol. Effective catalytic conditions were achieved using only 10% of catalyst 5 derived from diphenylvalinol in dioxane at 0°C resulting in complete conversion to the corresponding primary amine in up to 99% ee.
