128369-70-0Relevant articles and documents
Palladium-catalyzed transprotection of allyloxycarbonyl-protected amines: Efficient one-pot formation of amides and dipeptides
Roos,Bernabe,Hiemstra,Speckamp,Kaptein,Boesten
, p. 1733 - 1740 (1995)
The synthetic utility of the N-(allyloxycarbonyl) (Alloc) substituent in α-amino acid derivatives is substantially extended beyond its well-known function as an amine protecting group. When the palladium-catalyzed deprotection is carried out by using tributyltin hydride as nucleophile (the Guibe method) in the presence of an active acylating agent a new acyl group is introduced on nitrogen. Successful acylating agents include carboxylic acid anhydrides, acid chlorides, and activated esters. A useful example of this methodology is the removal of the Alloc group in the presence of tert-butyl dicarbonate, which in essence amounts to a 'transprotection' to a Boc-protected α-amino acid derivative. More importantly, the use of activated N-protected α-amino ester derivatives (e.g., pentafluorophenyl esters) leads to dipeptides. This new method for peptide coupling proceeds very fast under mild conditions, in good to excellent yields, and without noticeable racemization.
Substrate-directed lewis-acid catalysis for peptide synthesis
Muramatsu, Wataru,Hattori, Tomohiro,Yamamoto, Hisashi
supporting information, p. 12288 - 12295 (2019/08/20)
A Lewis-acid-catalyzed method for the substrate-directed formation of peptide bonds has been developed, and this powerful approach is utilized for the new "remote" activation of carboxyl groups under solvent-free conditions. The presented method has the following advantages: (1) the high-yielding peptide synthesis uses a tantalum catalyst for any amino acids; (2) the reaction proceeds without any racemization; (3) the new substrate-directed chemical ligation using the titanium catalyst is applicable to convergent peptide synthesis. These advantages overcome some of the unresolved problems in classical peptide synthesis.
