Enantioselective synthesis of non-proteinogenic amino acids via metallated bis-lactim ethers of 2,5-diketopiperazines
作者:Ulrich Schöllkopf
DOI:10.1016/s0040-4020(01)91926-x
日期:1983.1
excess = asymmetric induction) of the adduct exceeds 95%. On hydrolysis the adducts are cleaved liberating the chiral auxiliary (used to build up the bis-lactim ether 1) and the target molecules, the opticallyactive amino acid methyl esters of type 8,19,25 or 36. The two amino acid esters are separable either by fractional distillation or (eventually after further hydrolysis to amino acids) by chromatography
Chemo-enzymatic synthesis of all isomeric 3-phenylserines and -isoserines
作者:H. Hönig、P. Seufer-Wasserthal、H. Weber
DOI:10.1016/s0040-4020(01)90519-8
日期:1990.1
prepared from cinnamic acid derivatives or viaaldolcondensations of benzaldehyde and suitable enolates in few steps. These racemates were resolved with lipases from Candida cylindracea (CC) and Pseudomonas fluorescens (P) and the obtained products were hydrogenated to 3-phenylserines and -isoserines. The influence of the acyl group in the enzymatic resolution of erythro-3-azido-2-acyloxy-3-phenylpropionic
Enantio- and Diastereoselective Hydrogenation via Dynamic Kinetic Resolution by a Cationic Iridium Complex in the Synthesis of β-Hydroxy-α-amino Acid Esters
Anti-selective asymmetric hydrogenation of alpha-amino-beta-keto estersviadynamickineticresolution under low hydrogen pressure has been achieved by an easily-handled cationic iridium complex with tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BARF) as a counterion.
Homogeneous chiral nickel-bisphosphine complexes catalyze the asymmetric hydrogenation of α-amino-β-keto ester hydrochlorides through dynamic kinetic resolution to efficiently afford anti-β-hydroxy-α-amino esters with high diastereo- and enantioselectivities.