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Azido Amino Acids and Click Chemistry Building Blocks

In 2002, K. Barry Sharpless  and Morton Mendel  independently reported the copper-catalyzed Huisgen azide alkyne 1,3-cycloaddition reaction has become synonymous CLICK chemistry. 

Generic click reaction


The Cu(I) catalyzed cycloaddition reaction generates exclusively 1,4-substituted 1,2,3-triazoles. Utilization of a ruthenium catalyst provides the complimentary 1,5-disubstituted triazoles.

Ru cat click






The cycloaddition reaction can be performed while the peptide is still attached to the resin or in solution following cleavage.

Click chemistry utilizing the Cu(I) catalyzed Huisgen cycloaddition between an azide and an alkyne is a convenient way of preparing tagged peptides and cyclized peptides. The azides and alkynes do not need protecting groups during peptide synthesis by either Fmoc or Boc protocols. The post synthetic modification of the peptide can be performed directly, in high yield, without selective deprotection schemes.

Click chemistry is a convenient method of preparing stapled peptides (Ø. Jacobsen, et al., J. Org. Chem. 2011, 76, 1228-38; S.A. Kawamoto, et al., J Med Chem. 2012, 55, 1137-46).  Instead of forming the staple by ring closing metathesis, the bridging structure is formed through a cycloadditin reaction.

AAPPTec provides high purity click chemistry reagents at very competitive prices. 

generic Fmoc-azido amino acid

UFK120 Fmoc-Abu(N3)-OH  n=2

UFK220 Fmoc-D-Abu(N3)-OH     n=2

UFO130 Fmoc-Nva(N3)-OH     n=3

UFO230 Fmoc-D-Nva(N3)-OH    n=3

AFK142 Fmoc-Lys(N3)-OH     n=4

AFK242 Fmoc-D-Lys(N3)-OH     n=4


alpha-Me azido AA

UFA144     (S)-Fmoc-2-(4'-azidobutyl)alanine     n=4

UFA145     (S)-Fmoc-2-(5'-azidopentyl)alanine     n=5

UFA146     (S)-Fmoc-2-(6'-azidohexyl)alanine     n=6



UFG135     Fmoc-Pra-OH

UFG235     Fmoc-D-Pra-OH



UFA140     (S)-Fmoc-2-propargylalanine

UFA240     (R)-Fmoc-2-propargylalanine

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