51328-61-1Relevant articles and documents
Studies on the asymmetric reduction of β-oximino methyl ether boronates: Reagent control, double diastereocontrol and transmitted remote asymmetric induction
Sailes, Helen E.,Watts, John P.,Whiting, Andrew
, p. 3362 - 3374 (2007/10/03)
High asymmetric induction (94% ee) could be obtained in the reduction of the achiral E-oxime ether boronate 5 with a homochiral oxazaborolidine 13-BH3-THF complex. Application of this homochiral reducing agent system to non-aromatic oxime ethers 21 produced low to moderate asymmetric induction. Application of the same homochiral reducing agent system to reduction of homochiral boronate E-oximes 3 and 4 produced extreme double diastereo-selection effects, i.e. 8 and 95% ee respectively, which demonstrated that remote asymmetry was being 'transmitted' by a suitable choice of a 'partner' molecule from the boronate moiety to the oxime during reduction. However, attempts to obtain direct remote asymmetric induction in the reduction of homochiral β-oximino boronate methyl ethers 3 and 4 to the corresponding amines produced zero, with for example BH3-THF complex, up to 28% ee with an Et3N-BH3-THF mixture (after oxidative boronate ester cleavage).
The degradation of hydroxyamine derivatives with phosphoric acid
Auterhoff,Bertram
, p. 881 - 888 (2007/10/04)
-