1604-49-5Relevant articles and documents
Synthesis of C-Mannosylated Glycopeptides Enabled by Ni-Catalyzed Photoreductive Cross-Coupling Reactions
Mao, Runyu,Xi, Shiyi,Shah, Sayali,Roy, Michael J.,John, Alan,Lingford, James P.,G?de, Gerd,Scott, Nichollas E.,Goddard-Borger, Ethan D.
, p. 12699 - 12707 (2021)
The biological functions of tryptophan C-mannosylation are poorly understood, in part, due to a dearth of methods for preparing pure glycopeptides and glycoproteins with this modification. To address this issue, efficient and scalable methods are required for installing this protein modification. Here, we describe unique Ni-catalyzed cross-coupling conditions that utilize photocatalysis or a Hantzsch ester photoreductant to couple glycosyl halides with (hetero)aryl bromides, thereby enabling the α-C-mannosylation of 2-bromo-tryptophan, peptides thereof, and (hetero)aryl bromides more generally. We also report that 2-(α-d-mannopyranosyl)-L-tryptophan undergoes facile anomerization in the presence of acid: something that must be considered when preparing and handling peptides with this modification. These developments enabled the first automated solid-phase peptide syntheses of C-mannosylated glycopeptides, which we used to map the epitope of an antibody, as well as providing the first verified synthesis of Carmo-HrTH-I, a C-mannosylated insect hormone. To complement this approach, we also performed late-stage tryptophan C-mannosylation on a diverse array of peptides, demonstrating the broad scope and utility of this methodology for preparing glycopeptides.
A fast and direct iodide-catalyzed oxidative 2-selenylation of tryptophan
Gao, Yu-Ting,Liu, Shao-Dong,Cheng, Liang,Liu, Li
, p. 3504 - 3507 (2021/04/12)
A metal-free 2-selenylation of tryptophan derivatives is reported, where the use of iodide as the catalyst and oxone as the oxidant is key to obtain high yields. Various functional groups within the di-seleny and the indole ring are tolerated, and no racemization is generally observed.
Cyclotryptophan Mycotoxins: Short Synthesis of the Desymmetrized meso -Chimonantine Core of Leptosin C
Olaizola, Iurre,Abdine, Racha Abed Ali,Dhimane, Hamid,Dalko, Peter I.
, p. 391 - 396 (2016/12/24)
The desymmetrized meso-chimonantine core of leptosin C was prepared in a short stereoselective convergent sequence in 5 steps as the longest linear path from methyl l-tryptophan hydrochloride as starting material. The key step of this approach was a diastereoselective [4+2] cycloaddition between the bromooxindole and tryptophan derivatives allowing to define the adjacent quaternary benzylic centers in a high chemical yield.
