Alexander R Mitchell

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C-Terminal peptide thioesters are key intermediates in the synthesis/semisynthesis of proteins and of cyclic peptides by native chemical ligation. They are prepared by solid-phase peptide synthesis (SPPS) or biosynthetically by protein splicing techniques. Until recently, the chemical synthesis of C-terminal alpha-thioester peptides by SPPS was largely(More)
C-terminal peptide alpha-thioesters are valuable intermediates in the synthesis/semisynthesis of proteins by native chemical ligation. They are prepared either by solid-phase peptide synthesis (SPPS) or biosynthetically by protein splicing techniques. The present paper reviews the different methods available for the chemical synthesis of peptide(More)
Optical ignition and initiation of energetic materials could thus far be only accomplished through lasers, with specific characteristics of high power, pulse length, wavelength, and a small target area that greatly inhibit their applications. Here, we report that an ignition and an initiation process, further leading to actual detonation, does occur for(More)
[reaction: see text] Peptide p-nitroanilides are useful compounds for studying protease activity; however, the poor nucleophilicity of p-nitroaniline makes their preparation difficult. We describe a new efficient approach for the Fmoc-based synthesis of peptide p-nitroanilides using an aryl hydrazine resin. Mild oxidation of the peptide hydrazide resin(More)
A novel mechanism for trifluoroacetylation in solid-phase peptide synthesis, independent of the coupling step, has been elucidated. It involves the presence of trifluoroacetoxymethyl groups on the resin support, which react with resin-bound amines by an intersite nucleophilic reaction. The trifluoroacetoxymethyl groups are generated from preexisting(More)
The amination of 1-X-3,5-dinitrobenzenes via the vicarious nucleophilic substitution of hydrogen (VNS) with 1,1,1-trimethylhydrazinium iodide (TMHI) in the presence of t-BuOK or NaOMe in DMSO was studied. It was observed (when X = OMe, OCH(2)CF(3), OCH(2)CF(2)CF(2)H, OPh) that the amination occurs regioselectively (ratio of ortho/para-isomers is(More)