203873-69-2Relevant academic research and scientific papers
Site-specific N-alkylation of peptides on the solid phase
Reichwein, John F.,Liskamp, Rob M. J.
, p. 1243 - 1246 (1998)
A convenient approach, featuring a Mitsunobu reaction, is described for the introduction of an alkyl group at a specific amide function of a peptide on the solid phase. This 'site-specific alkylation' procedure is illustrated with an N-ethyl scan of Leu-enkephalin.
DBU Catalysed Enantioselective Degradative Rearrangement: a Way to Tetrasubstituted 2-Aryl-2-Amino Esters
Loro, Camilla,Sala, Roberto,Penso, Michele,Foschi, Francesca
, p. 3983 - 3994 (2021/07/02)
Herein we report a catalytic, easily scalable protocol for the enantioselective synthesis of Tetrasubstituted α-aryl-α-amino acid derivatives, using a biphasic system composed by catalytic DBU in DME and aqueous solutions of Na2CO3. Under very mild reaction conditions, without using metal or chiral additives, this heterogeneous system promotes the degradative rearrangement of functionalized N-aryl sulphonyl α-amino esters into the corresponding tetrasubstituted 2-aryl-2-amino esters, with high enantiomeric ratios (up to 97.5:2.5) and good yields (up to 95%). (Figure presented.).
Synthesis of cyclic dipeptides by ring-closing metathesis
Reichwein, John F.,Liskamp, Rob M. J.
, p. 2335 - 2344 (2007/10/03)
Several cyclic dipeptides (4a-g and 9a-c) have been synthesized by 'amide-to-amide' cyclization of 2a-g and 8a-c, respectively, by means of ring-closing metathesis employing the Grubbs ruthenium catalyst. The influence of additives as well as the length of the amide substituent were studied. Best yields were obtained by cyclization in solution with either lithium fluoroacetate or α,α-dichlorotoluene as an additive.
