323196-01-6

Upstream product

• 55135-66-5 9-bromo-9-phenyl-9H-fluorene 
• 16338-48-0 L-allylglycine 
• 659726-50-8 tert-butyl (2S)-2-[N-(9-phenylfluoren-9-yl)amino]pent-4-enoate 
• 90600-20-7 (2S)-2-[(tert-butoxycarbonyl)amino]pent-4-enoic acid 
• 135722-56-4 ethyl (RS)-N-(tert-butoxycarbonyl)-2-aminopent-4-enoate 

Downstream Products

• 743442-79-7 t-butyl (2S,4R)-5-azido-2-N-(9-phenyl-9H-fluoren-9-yl)amino-4-N-(2-trimethylsilylethanesulfonyl)aminopentanoate 
• 743442-74-2 t-butyl (2S,4S)-5-azido-2-N-(9-phenyl-9H-fluoren-9-yl)amino-4-N-(2-trimethylsilylethanesulfonyl)aminopentanoate 
• 743442-80-0 t-butyl (2S,4R)-5-[N',N''-bis(benzyloxycarbonyl)guanidino]-2-N-(9-phenyl-9H-fluoren-9-yl)amino-4-N-(2-trimethylsilylethanesulfonyl)aminopentanoate 
• 743442-75-3 t-butyl (2S,4S)-5-[N',N''-bis(benzyloxycarbonyl)guanidino]-2-N-(9-phenyl-9H-fluoren-9-yl)amino-4-N-(2-trimethylsilylethanesulfonyl)aminopentanoate 

Relevant academic research and scientific papers

Iminoiodane mediated aziridination of α-allylglycine: Access to a novel rigid arginine derivative and to the natural amino acid enduracididine

The synthesis of fully protected aminodihydrohistidines in optically pure form is described starting from allylglycine derivatives. These compounds represent novel conformationally constrained analogues of arginine, one of them being, in addition, a protected form of the marine natural product, enduracididine. The key step of the strategy is a one-pot copper-catalyzed aziridination of t-butyl (S)-N-(9-phenyl-9H-fluoren-9-yl)allylglycinate ((S)-16) with 2-trimethylsilylethanesulfonamide in the presence of iodosylbenzene.

Selective tert-butyl ester deprotection in the presence of acid labile protecting groups with use of ZnBr2

Chemoselective hydrolysis of tert-butyl esters in the presence of other acid-labile groups has been explored by employing α-amino esters and ZnBr2 in DCM. Although N-Boc and N-trityl groups were found to the labile, PhF protected amines were compatible with these Lewis acid deprotection conditions such that a variety of N-(PhF)amino acids were prepared in good yields from their corresponding tert-butyl esters.

N-substituted 2-amino-4-pentenoic acids for amino acid protection and resolution

N-Substituted 2-amino-4-pentenoic acid derivatives employed for the protection of racemic amino acids were shown to be capable of permitting the chromatographic separation of R and S isomers. When N(α) was disubstituted with benzyl and phenylfluorenyl groups, the racemic amino acids could be separated with facility on open silica gel columns. Further, the optically pure N-protected amino acids so derived could be used for the preparation of misacylated suppressor transfer RNAs. (C) 2000 Elsevier Science Ltd.