610800-47-0

Upstream product

• 18598-74-8 methyl L-isoleucinate hydrochloride 
• 98-74-8 4-Nitrobenzenesulfonyl chloride 

Downstream Products

• 610800-53-8 N-methyl-N-4-nitrophenylsulfonyl-L-isoleucine methyl ester 
• 2577-46-0 L-isoleucine methyl ester 
• 1243655-13-1 N-ethyl-N-nosyl-L-isoleucine methyl ester 
• 852852-81-4 3-methyl-2-(4-nitrophenylsulphonamido)pentanoic acid 
• 1219815-38-9 (2S,3S)-methyl 2-(N-allyl-4-nitrophenylsulfonamido)-3-methylpentanoate 
• 42807-92-1 N-Methyl-isoleucinmethylester 

Relevant academic research and scientific papers

DBU Catalysed Enantioselective Degradative Rearrangement: a Way to Tetrasubstituted 2-Aryl-2-Amino Esters

Herein we report a catalytic, easily scalable protocol for the enantioselective synthesis of Tetrasubstituted α-aryl-α-amino acid derivatives, using a biphasic system composed by catalytic DBU in DME and aqueous solutions of Na2CO3. Under very mild reaction conditions, without using metal or chiral additives, this heterogeneous system promotes the degradative rearrangement of functionalized N-aryl sulphonyl α-amino esters into the corresponding tetrasubstituted 2-aryl-2-amino esters, with high enantiomeric ratios (up to 97.5:2.5) and good yields (up to 95%). (Figure presented.).

"One-pot" methylation of N-nosyl-α-amino acid methyl esters with diazomethane and their coupling to prepare N-methyl dipeptides

N-Nosyl-α-amino acid methyl esters are methylated quantitatively with diazomethane. After proper deprotection of the amino function by treatment with the reagent system mercaptoacetic acid/sodium methoxide, the obtained N-methyl amino acid methyl esters are coupled with N-Fmoe amino acid chlorides to afford the corresponding dipeptides. The obtained products do not show any detectable extent of racemization by 1H NMR and HPLC.