283589-06-0

Upstream product

• 141595-88-2 (R)-tert-butyl (1-bromo-3-phenylpropan-2-yl)carbamate 
• 106454-69-7 N-tert-butoxycarbonyl-D-Phenylalaninol 
• 5267-64-1 (R)-2-amino-3-phenylpropanol 
• 63-91-2 L-phenylalanine 
• 3182-95-4 L-Phenylalaninol 
• 150-30-1 Phenylalanine 
• 1795-98-8 rac-phenylalaninol 

Relevant academic research and scientific papers

Chiral N-Heterocyclic Carbene Ligands Bearing a Pyridine Moiety for the Copper-Catalyzed Alkylation of N-Sulfonylimines with Dialkylzinc Reagents

Amino acid-derived chiral imidazolium salts, each bearing a pyridine ring, were developed as N-heterocyclic carbene ligands. The copper-catalyzed asymmetric alkylation of various N-sulfonylimines with dialkylzinc reagents in the presence of these chiral imidazolium salts afforded the corresponding alkylated products with high enantioselectivity (up to 99 % ee). The addition of HMPA to the reaction mixture as a co-solvent is critical in terms of chemical yield and enantioselectivity. A wide range of N-sulfonylimines and dialkylzinc reagents were found to be applicable to this reaction. Amino acid-derived chiral imidazolium salts, each bearing a pyridine ring, were developed as N-heterocyclic carbene ligands. The copper-catalyzed asymmetric alkylation of various N-sulfonylimines with dialkylzinc reagents in the presence of these chiral imidazolium salts afforded the corresponding alkylated products with high enantioselectivity (up to 99 % ee; see scheme). A wide range of N-sulfonylimines and dialkylzinc reagents were found to be applicable to this reaction.

Synthesis of amidoalkyl imidazol-2-ylidene ligands and their application to enantioselective copper-catalysed conjugate addition

A small library of precursors to chiral amidoalkyl imidazol-2-ylidene ligand was synthesised via a two-step procedure starting from commercially available amino alcohols. Preliminary screening of these bidentate ligands for the enantioselective copper-catalysed conjugate addition of diethyl zinc to cyclohexenone revealed some moderate ee values. Related chiral iminoalkyl imidazole-2-ylidene ligands demonstrated much poorer enantioselectivity. The results indicate that chelation involving a covalent copper-nitrogen bond gives better selectivity than that arising from a dative copper-nitrogen co-ordination. Georg Thieme Verlag Stuttgart.

Synthesis of chiral iminoalkyl functionalised N-heterocyclic carbenes and their use in asymmetric catalysis

A library of new chiral iminoalkyl imidazolium salts has been synthesised from amino acids using a modular design approach. Deprotonation with silver oxide yields silver carbene transfer reagents, which can be used as ligand sources in asymmetric catalysis. Preliminary testing has shown that the ligands induce enantioselectivity in the palladium-catalysed allylic alkylation of 1,3-diphenylprop-3-enyl acetate with dimethyl malonate.

Synthesis and biological properties of novel sphingosine derivatives

Sphingosine-1-phosphate (S-1P) derivatives such as threo-(2S,3S)-analogues, which are C-3 stereoisomers of natural erythro-(2S,3R)-S-1P, have been synthesized starting from l-serine or (1S,2S)-2-amino-1-aryl-1,3-propanediols (6). threo-(1S,2R)-2-Amino-1-aryl-3-bromopropanols (HBr salt) have also been prepared from 6. The threo-S-1Ps and the threo-amino-bromide derivatives have shown potent inhibitory activity against Ca2+ ion mobilization in HL60 cells induced by erythro-S-1P, suggesting that these compounds would compete with cell surface EDG/S1P receptors.

Properties and Reactions of Substituted 1,2-Thiazetidine 1,1-Dioxides: Chiral Mono- and Bicyclic 1,2-Thiazetidine 1,1-Dioxides from α-Amino Acids

New chiral mono- and bicyclic β-sultams, valuable building blocks for drug synthesis, have been prepared from L-Ala, L-Val, L-Leu, L-Ile, L-Phe, L-Cys, L-Ser, L-Thr, and D-penicillamine by transformation of the COOH group into a methylsulfonyl chloride function, followed by cyclization under basic conditions. Selected properties, derivatives, and reactions of the β-sultams are described.

Efficient synthesis of β-amino bromides

β-Aminoalcohols were smoothly converted to β-amino bromides using thionyl bromide and DMF, which were easily isolated without any further purification. Participation by the β-amino group in brominations not only enhanced reaction rates but also promoted stereo- and regioselectivities. (C) 2000 Elsevier Science Ltd.