257628-08-3

Upstream product

• 13086-84-5 di-tert-butyl phosphite 
• 257628-10-7 L-N^α-benzyloxycarbonyl-4-(bromomethyl)phenylalanine benzyl ester 
• 257628-02-7 L-N^α-benzyloxycarbonyl-4-(1,2-dihydroxyethyl)phenylalanine benzyl ester 
• 257628-09-4 L-N^α-benzyloxycarbonyl-4-(hydroxymethyl)phenylalanine benzyl ester 
• 257628-01-6 L-N^α-benzyloxycarbonyl-4-[1-(2-ethenyl)]phenylalanine benzyl ester 
• 257628-03-8 L-N^α-benzyloxycarbonyl-4-(formyl)phenylalanine benzyl ester 
• 183070-41-9 L-N^α-Cbz-4-(O-trifluoromethanesulfonate)tyrosine benzyl ester 

Downstream Products

• 257628-04-9 L-4-((di-tert-butyl)phosphonomethyl)phenylalanine 

Relevant academic research and scientific papers

Preparation of L-N(α)-Fmoc-4-[di-(tert- butyl)phosphonomethyl]phenylalanine from L-tyrosine

The unnatural amino acid analogue, 4-(phosphonomethyl)phenylalanine (Pmp, 2), has proven to be a valuable tool for studying protein-tyrosine kinase dependent signal transduction, where it is most often incorporated into peptides or peptide mimetics as a phosphatase-stable phosphotyrosyl mimetic. Although Pmp has been prepared previously bearing a number of protection strategies, the N(α)-Fmoc 4-[di-(tert-butyl)phosphonomethyl] phenylalanine form [(N(α)-Fmoc-L-Pmp((t)Bu2)-OH, 3] is particularly attractive since it can be cleanly introduced into peptides using standard Fmoc protocols. Synthesis of 3 was first reported as its (D/L)-racemate, and subsequently as its L-3 enantiomer, with the latter synthesis having relied on induction of chirality using a camphor sultam auxillary. Reported herein is an alternate enantioselective synthesis of L-3 in high enantiomeric purity by procedures which derive the stereochemistry of the final product directly from the starting amino acid, without the need for chiral induction. A key feature of the route is the racemization-free nucleophilic substitution of lithium di-tert-butyl phosphite onto protected 4-bromomethylphenylalanine (17).