128113-78-0Relevant academic research and scientific papers
Design, synthesis, and optical resolution of a novel non-natural chiral auxiliary, 1-(2,5-dimethoxyphenyl)ethylamine. Application to diastereoselective alkylation of aldimines
Kohara, Takehiro,Hashimoto, Yukihiko,Saigo, Kazuhiko
, p. 6453 - 6464 (2007/10/03)
A chiral amine; 1-(2,5-dimethoxyphenyl)ethylamine, was found to be an effective chiral auxiliary for the diastereoselective alkylation of its aldimines with alkylmetals. The 1-(2,5-dimethoxyphenyl)ethyl group of the chiral auxiliary could be removed by the acetylation and then oxidation of the resultant alkylated product, accompanying an amino-transfer from the chiral auxiliary to the final product. Racemic 1-(2,5- dimethoxyphenyl)ethylamine could be easily synthesized from 1,4- dimethoxybenzene and resolved by the diastereomeric salt formation with mandelic acid to give both enantiomers in pure forms.
Chiral Building Blocks for the Synthesis of Nitrogen-Containing Natural Products, 5. The Enantioselective Synthesis of Optically Active, Benzene Nucleus-Substituted 1-Phenylethylamines from the Corresponding Acetophenones
Bringmann, Gerhard,Geisler, Joerg-Peter,Geuder, Torsten,Kuenkel, Georg,Kinzinger Lioba
, p. 795 - 805 (2007/10/02)
An efficient two-step procedure for the synthesis of enantiomerically pure, benzene nucleus-substituted 1-phenylethylamines 1 is described, with predictable absolute configuration at the stereogenic center: Imine formation from the substituted acetophenones 6 with (S)- or (R)-1-phenylethylamine and subsequent hydrogenation of the resulting Schiff bases 8 over Raney nickel leads to the secondary amines 9 and 10 in high diastereoselectivities.These dibenzylamines are cleaved regioselectively, usually next to the less substituted aromatic ring, giving the desired chiral 1-phenylethylamines 1 in high yields and enantiomeric purities.Scope and limitations of this new and facile approach to the versatile building blocks 1 are reported.
