85992-81-0Relevant academic research and scientific papers
Synthesis of benzene-1-alanine-3-glycine as carba analogues of cystine
Furenes, Eline Bredal,Luijendijk, Jaco,Efskind, Jon,Undheim, Kjell
, p. 193 - 200 (2007/10/03)
Methodology has been developed for the synthesis of C4-carba- bridged cystine analogues with a 1,3-disubstituted phenyl group inserted into the chain. Stereoselective bromobenzylation of the Schoellkopf chiron and a subsequent bromine-lithium e
Catalytic, asymmetric Mannich-type reactions of N-acylimino esters: Reactivity, diastereo- and enantioselectivity, and application to synthesis of N-acylated amino acid derivatives
Kobayashi, Shu,Matsubara, Ryosuke,Nakamura, Yoshitaka,Kitagawa, Hidetoshi,Sugiura, Masaharu
, p. 2507 - 2515 (2007/10/03)
In the presence of a catalytic amount of Cu(OTf)2-chiral diamine 3e complex, N-acylimino esters reacted with silyl enol ethers to afford the corresponding Mannich-type adducts in high yields with high enantioselectivities. A wide variety of silyl enol ethers derived from ketones, as well as esters and thioesters, reacted smoothly. In the reactions of α-substituted silyl enol ethers (α-methyl or benzyloxy), the desired syn-adducts were obtained in high yields with high diastereo- and enantioselectivities. Several intermediates for the synthesis of biologically important compounds were prepared using this novel catalytic asymmetric Mannich-type reaction, and at the same time, absolute and relative stereochemical assignments were made. In addition, it has been revealed that alkyl vinyl ethers reacted with N-acylimino esters in the presence of a catalytic amount of the Cu(II) catalyst to give the corresponding Mannich-type adducts in high yields with high enantioselectivities. This is the first example of catalytic asymmetric Mannich-type reactions with alkyl vinyl ethers. The reaction mechanism, structure of chiral catalyst-electrophile complexes, and transition states of these catalytic asymmetric reactions were assumed based on X-ray crystallographic analysis of the Cu(II)-chiral amine complex, PM3 calculations, and FT-IR analyses, etc. Finally, (1R,3R)-N-(3-hydroxy- 1-hydroxymethyl-3-phenylpropyl)dodecanamide (HPA-12, 1), a new inhibitor of ceramide trafficking from endoplasmic reticulum to the site of sphingomyerin (SM) synthesis, has been synthesized efficiently using the present Mannich-type reaction as a key step. The synthesis involved three steps (two-pot), and total yield was 82.9%.
NEW SYNTHESES OF α-AMINO ACIDS BASED ON N-ACYLIMINO ACETATES
Bretschneider, Thomas,Miltz, Wolfgang,Muenster, Peter,Steglich, Wolfgang
, p. 5403 - 5414 (2007/10/02)
The reaction of N-acylamino-2-bromoacetates 2 ( via N-acylimino acetates 3 ) with higher order mixed cuprates, trimethylsilyl enol ethers and β-dicarbonyl compounds leads to a variety of α-amino acid derivatives.Their conversion into the free amino acids can be conveniently carried out by the use of t-butyl protection.In case of the N-acetyl compounds cleavage of the protecting group and optical resolution can be achieved in one step hog renal acylase.
SYNTHESIS OF DIASTEREO- AND ENANTIOMERICALLY PURE α-AMINO-γ-OXO ACID ESTERS BY REACTION OF ACYLIMINOACETATES WITH ENAMINES DERIVED FROM 6-MEMBERED KETONES
Kober, Reiner,Papadopoulos, Kyriakos,Miltz, Wolfgang,Enders, Dieter,Steglich, Wolfgang,et al.
, p. 1693 - 1702 (2007/10/02)
A new efficient diastereo- and enantioselective synthesis of α-amino-γ-oxo acid esters by reaction of acyliminoacetates with enamines is described.By employing the concept of double stereodifferentiation, complete asymmetric induction (de=ee >/= 99.9 percent) for the C-C bond formation is obtained.Desulphurization of a sulphur containing product leads to the corresponding acyclic amino acid derivatives.The virtually complete anti-diastereo- and enantioselectivities are interpreted by a Diels-Alder like transition state.
Reaction of Acylaminobromomalonates and Acylaminobromoacetates with Trialkylphosphites - A Simple Synthesis of Ethyl 2-Amino-2-(diethoxyphosphoryl)acetate
Kober, Reiner,Steglich, Wolfgang
, p. 599 - 609 (2007/10/02)
Depending on the reaction conditions acylaminobromomalonates 1 and trialkylphosphites yield either 5-alkoxyoxazoles 7, 2-malonates 8, or 2-acylamino-2-(dialkoxyphosphoryl)malonates 2.N-Acylglucin esters 9 can be converted in
