241812-15-7Relevant articles and documents
Resin-bound dendrimers as high loading supports for solid phase chemistry
Mahajan, Anju,Chhabra, Siri Ram,Chan, Weng C.
, p. 4909 - 4912 (1999)
The synthesis of a tris-Boc tri-amino acid and its utility in the generation of dendrimers as inert scaffolds on solid supports is described. These high loading amine functionalized resins were successfully used in the synthesis of small molecules.
Homochiral 4-azalysine building blocks: Syntheses and applications in solid-phase chemistry
Chhabra, Siri Ram,Mahajan, Anju,Chan, Weng C.
, p. 4017 - 4029 (2007/10/03)
Anomalous amino acids not only play central roles as mimics of natural amino acids but also offer opportunities as unique building blocks for combinatorial chemistry. This paper describes the chiral syntheses and solid-phase applications of a versatile atypical amino acid, 4-azalysine (2,6-diamino-4-azahexanoic acid) 1. The syntheses of differentially protected 4-azalysine derivatives 28a-e have been developed by two efficient and inexpensive routes that start either from Garner's aldehyde 16 or the chiron (S)-Nα-Cbz-2,3-diaminopropionic acid 23. Both approaches employ the convergent modular concept and exploit reductive amination of aldehydes with amines as the key step for the fusion of the two segments. In the first route, the overall process inverts the chirality of the starting material, L-serine, and thus provides an excellent route to the unnatural D-isomers. The alternative route starting from L-asparagine provides a shorter and high-yielding route to orthogonally protected 4-azalysine derivatives. The corresponding N2-Fmoc-4-azalysines 31a-e, readily derived from the key intermediate 27, are compatible with the Fmoc-based solid-phase peptide synthesis (SPPS) and solid-phase organic chemistry (SPOC) protocols. Furthermore, the utility and versatility of another key structure, tris-Boc-4-azalysine 2 in the engineering of novel high-loading dendrimeric polystyrene resins 33 and 36, have been demonstrated. Following derivatization with the Rink amide linker 34, the stability and robustness of these resin-bound dendrimers 35 and 37 in the synthesis of small molecules using a range of reaction conditions (e.g., Mitsunobu and Suzuki reactions) have been effectively illustrated.
Synthesis of novel, orthogonally protected multifunctional amino acids
Chhabra, Siri Ram,Mahajan, Anju,Chan, Weng C.
, p. 4905 - 4908 (2007/10/03)
Two synthetic strategies for the generation of differentially protected, chiral tri-amino acids have been developed. The first strategy is based on the reductive amination of a serine-derived oxazolidine aldehyde with mono N- protected ethylenediamine. The second approach involves reductive alkylation of an asparagine-derived N-protected diaminopropionate with an N-protected glycinal. The newly generated secondary amine functionality is derivatised to furnish structurally diverse molecules.
