50707-28-3Relevant academic research and scientific papers
Enhancing activity and controlling stereoselectivity in a designed PLP-dependent aldolase
Toscano, Miguel D.,Mueller, Manuel M.,Hilvert, Donald
, p. 4468 - 4470 (2007)
Chop and change: Site-directed mutagenesis has been employed to optimize the activity of an engineered pyridoxal phosphate-dependent aldolase and to invert its inherent threo selectivity in the cleavage of D-β-phenylserines. The modification of the active-site residues generates significant retroaldol activity that compares favorably with that of natural enzymes in terms of efficiency and selectivity.
Catalytic asymmetric hydrogenation of α-amino-β-keto ester hydrochlorides using homogeneous chiral nickel-bisphosphine complexes through DKR
Hamada, Yasumasa,Koseki, Yu,Fujii, Takefumi,Maeda, Tsukuru,Hibino, Takuya,Makino, Kazuishi
supporting information; scheme or table, p. 6206 - 6208 (2009/05/06)
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 enantioselectivit
Enantio- and diastereoselective hydrogenation via dynamic kinetic resolution by a cationic iridium complex in the synthesis of β-hydroxy-α-amino acid esters
Makino, Kazuishi,Iwasaki, Masamichi,Hamada, Yasumasa
, p. 4573 - 4576 (2007/10/03)
Anti-selective asymmetric hydrogenation of α-amino-β-keto esters via dynamic kinetic resolution 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 co
CHEMO-ENZYMATIC SYNTHESIS OF ALL ISOMERIC 3-PHENYLSERINES AND -ISOSERINES
Hoenig, H.,Seufer-Wasserthal, P.,Weber, H.
, p. 3841 - 3850 (2007/10/02)
The synthesis of all isomers of 3-phenylserines and 3-phenylisoserines in enantiomerically pure form is presented.Diastereomerically pure educts (threo/erythro-2-azido-3-butanoyloxy-3-phenyl-propionic esters, threo/erythro-3-azido-2-butanoyloxy-3-phenylpropionic esters, threo-2-butanoylamino-3-butanoyloxy-3-phenylpropionic ester, erythro-3-butanoylamino-2-butanoyloxy-3-phenyl-propionamide) were prepared from cinnamic acid derivatives or via aldol condensations 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 esters was investigated.
ENANTIOSELECTIVE SYNTHESIS OF NON-PROTEINOGENIC AMINO ACIDS VIA METALLATED BIS-LACTIM ETHERS OF 2,5-DIKETOPIPERAZINES
Schoellkopf, Ulrich
, p. 2085 - 2092 (2007/10/02)
Bis-lactim ethers 1 of 2,5-diketopiperazines contain a chiral inducing center, an acidic CH-bond and two sites susceptible to hydrolysis.They react with BuLi to give Li compounds of type 4, 15, 29 or 32, which possess a prochiral C atom.They readily add electrophiles (such as alkylating agents or carbonyl compounds) with unusually high diastereoface differentiation.In many cases the d.e-value (d.e. = diastereomeric excess = asymmetric induction) of the adduct exceeds 95percent.On hydrolysis the adducts are cleaved liberating the chiral auxiliary (used to build up the bis-lactim ether 1) and the target molecules, the optically active 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.Transition state models are discussed that could explain the exceptionally high asymmetric induction and the predictability of the induced configuration.
