situations a useful peptide coupling additive. Uronium and phosphonium salts with HODhat built into the system were also useful stand-alone couplingreagents. Comparisons with related additives and couplingreagents showed that the new systems were sometimes more and sometimes less effective than previously described systems in the case of stepwise and segment couplings. Applications to assembly of
The diisopropylcarbodiimide/ 1-hydroxy-7-azabenzotriazole system: Segment coupling and stepwise peptide assembly
作者:Louis A Carpino、Ayman El-Faham
DOI:10.1016/s0040-4020(99)00344-0
日期:1999.5
although the relative order of efficiency was similar in solvents such as DMF in which more extensive epimerization resulted. In application of to stepwise peptide assembly by solid phase techniques, it was found that the hindered pyridine base collidine enhanced the step involying preactivation of the carboxylic acid residue in contrast to the normal situation in which bases such as DIEA, NMM, or non-hindered
Comparison of the Effects of 5- and 6-HOAt on Model Peptide Coupling Reactions Relative to the Cases for the 4- and 7-Isomers<sup>,</sup>
作者:Louis A. Carpino、Hideko Imazumi、Bruce M. Foxman、Michael J. Vela、Peter Henklein、Ayman El-Faham、Jana Klose、Michael Bienert
DOI:10.1021/ol006013z
日期:2000.7.1
[GRAPHICS]Synthesis of 5- and 6-HOAt has completed the full set of the four HOAt isomers derived from HOBt by insertion of a single nitrogen atom in the benzenoid nucleus. Comparison of the reactivity of all four isomers in model peptide coupling reactions has confirmed the unique character of the 7-isomer in promoting selectivity and maintaining configuration at the reactive carboxylic acid residue.
Carpino, Louis A.; Imazumi, Hideko; El-Faham, Ayman, Angewandte Chemie - International Edition, 2002, vol. 41, # 3, p. 442 - 445
作者:Carpino, Louis A.、Imazumi, Hideko、El-Faham, Ayman、Ferrer, Fernando J.、Zhang, Chongwu、Lee, Yunsub、Foxman, Bruce M.、Henklein, Peter、Hanay, Christiane、Muegge, Clemens、Wenschuh, Holger、et al.
DOI:——
日期:——
A Novel Family of Onium Salts Based Upon Isonitroso Meldrum's Acid Proves Useful as Peptide Coupling Reagents
new family of uronium salts (HTMU, HMMU, and HDmPyMU) based on isonitroso Meldrum's acid (HONM) are reported as stand-alone couplingreagents. Amide bond formation with the use of these reagents occurred more quickly than that with other uronium salts as a result of the presence of a neighboring group effect with a cyclic structure. Thus, these novel onium salts were often moreeffective in the acylation