[EN] A CATALYTIC ASYMMETRIC METHOD FOR THE PREPARATION OF THE PACLITAXEL (TAXOL) C-13 SIDE-CHAIN DERIVATIVES AND ITS USE IN THE PREPARATION OF TAXANE DERIVATIVES [FR] PROCÉDÉ ASYMÉTRIQUE CATALYTIQUE POUR LA PRÉPARATION DE DÉRIVÉS DE LA CHAÎNE LATÉRALE C-13 DU PACLITAXEL (TAXOL) ET SON UTILISATION DANS LA PRÉPARATION DE DÉRIVÉS DU TAXANE
Highly Enantioselective Organocatalytic Addition of Aldehydes to<i>N</i>-(Phenylmethylene)benzamides: Asymmetric Synthesis of the Paclitaxel Side Chain and Its Analogues
Easily side‐tracked: A simple route to the paclitaxel side chain and its analogues is based on the (R)‐proline‐catalyzed addition of aldehydes to N‐(phenylmethylene)benzamides, followed by oxidation of the resulting protected α‐hydroxy‐β‐benzoylaminoaldehydes (92–99 % ee). Esterification of the subsequent phenylisoserine derivatives with baccatin III gives paclitaxel analogues (see scheme).
One-pot highly enantioselective catalytic Mannich-type reactions between aldehydes and stable α-amido sulfones: asymmetric synthesis of β-amino aldehydes and β-amino acids
A highlyenantioselective catalytic route to carbamate- and benzoate-protected β-amino aldehydes and β-amino acids is presented. The amino acid-catalyzed one-pot asymmetric reaction between unmodified aldehydes and α-amido sulfones gives the corresponding β-amino compounds with up to 95:5 dr and 97–>99% ee.