A novel three-component carbon-carbon forming reaction is discovered. Reaction of methyl phenyldiazoacetate with both imine and arylamine in the presence of dirhodium acetate catalyst gives good yields of 1,2-diamines...A novel three-component carbon-carbon forming reaction is discovered. Reaction of methyl phenyldiazoacetate with both imine and arylamine in the presence of dirhodium acetate catalyst gives good yields of 1,2-diamines 5 in competition with N-H insertion to yield 4. While the product ratio is dependent on the electronic features from aryl substitution of the corresponding amine, diastereoselectivity of 5 was consistently high (greater than 10:1 ). Although N-H insertion is competitive, this pathway can be minimized by the use of excess imine. A plausible mechanism revealed that the key intermediate is proposed to be ammonium ylide. This discovery is useful for the preparation of 1,2-diamines with high diastereoselectivity.……展开更多
Alkylation of the ketimine 2 obtained from condensation of (+)-ketopinic acid and benzyla- mine with a variety of alkylating agents gives the products whose trends in diastereomeric excesses (1- 100% O. P.) appear to ...Alkylation of the ketimine 2 obtained from condensation of (+)-ketopinic acid and benzyla- mine with a variety of alkylating agents gives the products whose trends in diastereomeric excesses (1- 100% O. P.) appear to correlate with the structure and reactivity of electrophilic agents. Using excess n-butyl lithium and allylic or benzylic halides, β-alkylation occured.展开更多
The carbonyl addition of the pinanone ketimine derived from (+) or (-)-2-hydroxy-pinan- 3-one and benzylamine has been studied and the optically active α,β-substituted-β-aminoethanol deriva- tives were obtained in ...The carbonyl addition of the pinanone ketimine derived from (+) or (-)-2-hydroxy-pinan- 3-one and benzylamine has been studied and the optically active α,β-substituted-β-aminoethanol deriva- tives were obtained in good chemical yields (36.5-69.5%) with optical purity ranging from 1.4% to 99.9%.展开更多
文摘A novel three-component carbon-carbon forming reaction is discovered. Reaction of methyl phenyldiazoacetate with both imine and arylamine in the presence of dirhodium acetate catalyst gives good yields of 1,2-diamines 5 in competition with N-H insertion to yield 4. While the product ratio is dependent on the electronic features from aryl substitution of the corresponding amine, diastereoselectivity of 5 was consistently high (greater than 10:1 ). Although N-H insertion is competitive, this pathway can be minimized by the use of excess imine. A plausible mechanism revealed that the key intermediate is proposed to be ammonium ylide. This discovery is useful for the preparation of 1,2-diamines with high diastereoselectivity.……
基金The subject was supported by the National Natural Science Foundation of China
文摘Alkylation of the ketimine 2 obtained from condensation of (+)-ketopinic acid and benzyla- mine with a variety of alkylating agents gives the products whose trends in diastereomeric excesses (1- 100% O. P.) appear to correlate with the structure and reactivity of electrophilic agents. Using excess n-butyl lithium and allylic or benzylic halides, β-alkylation occured.
基金This project is supported by the National Natural Science Foundation of China
文摘The carbonyl addition of the pinanone ketimine derived from (+) or (-)-2-hydroxy-pinan- 3-one and benzylamine has been studied and the optically active α,β-substituted-β-aminoethanol deriva- tives were obtained in good chemical yields (36.5-69.5%) with optical purity ranging from 1.4% to 99.9%.
