Synthesis of 3-aminoaspartic acid derivatives from glycine precursors
作者:Yu Chen、Andrei K. Yudin
DOI:10.1016/s0040-4039(03)01122-5
日期:2003.6
3-Aminoaspartic acidderivatives 3 have been synthesized via stereoselective alkylation of α-acetyloxyglycine Schiff base 2 with the enolate of glycine anion equivalent 1 as a carbon nucleophile in the presence of Pd(OAc)2 and BINAP at room temperature. High chemical yields and moderate stereoselectivities were observed. The enantiomeric excess of the dl diastereomer can be increased to 95% after a
Synthesis of β,γ-unsaturated amino acid derivatives by alkyne carbometalation-palladium catalyzed coupling with 2-aza-π-allyl palladium complexes
作者:Martin J. O'Donnell、Min Li、William D. Bennett、Todd Grote
DOI:10.1016/s0040-4039(00)78548-0
日期:1994.12
Zirconium-catalyzed carboalumination of terminal or symmetrical internal alkynes followed by palladium-catalyzed coupling of the resulting vinylalane with Schiff base acetate 1 gives protected β,γ-unsaturated amino acid derivatives (vinylglycines) 6.
2-aza-π-allylpalladium complexes for the synthesis of β-carboxyaspartic acid (asa) derivatives
作者:Martin J. O'Donnell、Xiaobei Yang、Min Li
DOI:10.1016/s0040-4039(00)97824-9
日期:1990.1
Palladium-catalyzed reaction of a malonate anion with a glycine cation equivalent: Bis-phosphine ligands and in situ catalyst formation
作者:Martin J O'Donnell、Changyou Zhou、Aiqiao Mi、Ning Chen、Jeffrey A Kyle、Pher G Andersson
DOI:10.1016/0040-4039(95)00795-e
日期:1995.6
Sodium dimethyl malonate couples effectively with Schiff base acetate 1 using
Efficient Catalytic Enantioselective Reaction of a Glycine Cation Equivalent with Malonate Anions <i>via</i> Palladium Catalysis
作者:Martin J. O'Donnell、Ning Chen、Changyou Zhou、Angela Murray、Clifford P. Kubiak、Fan Yang、George G. Stanley
DOI:10.1021/jo961869w
日期:1997.6.13
The enantioselective alkylation of Schiff base acetates 1 with malonate types of stabilized carbon nucleophiles in the presence of a stable palladium source Pd(OAc)(2) and the chiral ligand (+)-BINAP was developed. The product 2, a protected beta-carboxyaspartic acid (ASA), was obtained in up to 85% enantiomeric excess by varying the ester protecting group on the substrate. The nature of the nucleophile has a significant effect on the enantioselectivity in this (2-aza-pi-allyl)palladium system. While a rapid chemical conversion was achieved with Schiff base benzoates 5, the enantioselectivity was insensitive to the leaving group used. An optically active substrate (51% ee) gave the same level of enantioselectivity as that obtained from the racemate. Temperature effects on the reaction were also studied; the best selectivity was obtained at 0 degrees C. A laboratory-scale reaction of the reactive nucleophile KCH(COOCH3)(2) with the tert-butyl ester substrate 1c gave, following a single recrystallization, product 2c with 95.5% ee in an overall chemical yield of 62%.