Direct organocatalytic asymmetric Mannich-type reactions in aqueous media: one-pot Mannich-allylation reactions
作者:Armando Córdova、Carlos F Barbas
DOI:10.1016/s0040-4039(03)00019-4
日期:2003.2
organocatalytic asymmetric Mannich-type reactions in aqueousmedia are demonstrated herein. l-Proline-catalyzed reactions in aqueousmedia to provide β-formyl substituted α-amino acid derivatives with excellent diastereoselectivities (dr up to 19:1, syn/anti) and high enantioselectivities (ee between 72 and >99%). These conditions provided for the development of novel one-potasymmetric syntheses of cyclic
anti-Selective SMP-catalyzed direct asymmetric Mannich-type reactions: synthesis of functionalized amino acid derivatives
作者:Armando Córdova、Carlos F Barbas
DOI:10.1016/s0040-4039(02)01772-0
日期:2002.10
The first (S)-2-methoxymethylpyrrolidine (SMP)-catalyzed direct asymmetricMannich-type reactions of unmodified aldehydes with N-PMP-protected α-imino ethyl glyoxylate are described. The reaction proceeded in a highly anti-selective manner (dr up to 19:1) with enantioselectivities between 74 and 92%.
One-Pot Asymmetric Synthesis of β-Cyanohydroxymethyl α-Amino Acid Derivatives: Formation of Three Contiguous Stereogenic Centers
作者:Shin-ichi Watanabe、Armando Córdova、Fujie Tanaka、Carlos F. Barbas
DOI:10.1021/ol027048x
日期:2002.12.1
[reaction: see text] One-pot asymmetric Mannich-hydrocyanation reactions are described. Reaction of unmodified aldehydes with N-PMP-protected alpha-imino ethyl glyoxylate in the presence of catalyticamounts of L-proline followed by the addition of Et(2)AlCN provided highly enantiomericallypure beta-cyanohydroxymethyl alpha-amino acid derivatives possessing three contiguous stereogenic centers as