A Stereocontrolled Nucleophilic Addition to Imines and a Catalytic Asymmetric Reaction

A stereocontrolled nucleophilic addition to imines and A catalytic asymmetric reaction are described1.当alpha-siloxy aldimines allowed to react with RLi followed by hydrolysis ofthe siloxy compounds， threo beta-amino alcohols被拒绝stereoselectively. However，to our great suprisethe reaction of alpha-siloxy aldimines with RCu . bf_3 afforded erythro compounds exclusively.2.Allylic bromides reacted with imines at 60゚C in acetonitrile to give the correspondinghomoallylamines in good yields in the presence of bismuth trichlorid -metallic zine。Diastereoselectivity of the present反应was investigated by using crotyl bromide-imines oroptically active imines-allyl bromide.3.它found that imines reacted with trimethylsilylcyanide in the presence of a catalytic amount of bismuth trichloride to afford alpha-amino nitrilesin good yields. Enantionselective cyanation of imines took place by using asymmetric bismuthcompound prepared from optically active ethyl tartrate。

A stereocontrolled nucleophilic addition to imines and a catalytic asymmetric reaction are described as follows.1. When alpha-siloxy aldimines were allowed to react with RLi followed by hydrolysis of the siloxy compounds, threo beta-amino alcohols were obtained stereoselectively. However, to our great suprise, the reaction of alpha-siloxy aldimines with RCu・BF_3 afforded erythro compounds exclusively.2. Allylic bromides reacted with imines at 60ﾟC in acetonitrile to give the corresponding homoallylamines in good yields in the presence of bismuth trichloride-metallic zine. Diastereoselectivity of the present reaction was investigated by using crotyl bromide-imines or optically active imines-allyl bromide.3. It was found that imines reacted with trimethylsilyl cyanide in the presence of a catalytic amount of bismuth trichloride to afford alpha-amino nitriles in good yields. Enantionselective cyanation of imines took place by using asymmetric bismuth compound prepared from optically active ethyl tartrate.