SYNTHESIS OF SOMEPARA-FUNCTIONALIZED PHENYLBORONIC ACID DERIVATIVES

Ortho-substituted aryl monoboronic acids have improved selectivity for d-glucose relative to d-fructose and l-lactate

“…9 and 10 were prepared by oxidation of the corresponding aldehydes with KMnO 4 . 40 Alizarin red sodium, D-glucose, D-fructose, L-lactate, P4417 (phosphate buffered saline pellets), and P7994 (phosphate buffer pellets) were purchased from SigmaeAldrich and used as received. Deionized water was used for the binding studies.…”

Synthesis of Boron-Containing Primary Amines

“… a In two steps; b 2a was also prepared under similar synthetic conditions [36]; c preparation of 2f using different synthetic conditions was also reported [37]. …”

Synthesis and Evaluation of Boronated Lysine and Bis(carboranylated) γ‐Amino Acids as Monomers for Peptide Assembly

“…An efficient synthesis of (4‐formylphenyl)boronic acid ( 1 ), allowing high‐yielding preparations of various phenylboronic acid derivatives, has been described 22. Among these, (4‐carboxyphenyl)boronic acid23 was selected here, as its coupling to the side‐chain ϵ‐amino group of N α ‐Fmoc‐ L ‐lysine appeared to be a straightforward procedure through which to obtain a boronated amino acid. Before doing so, however, it is necessary to esterify the boronic acid to provide a boronate that will be stable to the coupling/deprotection steps commonly encountered during peptide synthesis.…”

“…Each of these boronates was stable to piperidine, used to remove Fmoc groups during peptide synthesis, but only 6 and 7 were stable to 95% trifluoroacetic acid. Commercially available pinacol thus appeared to be a suitable esterification agent and so was selected for the subsequent preparation of boronated monomers; this resulted in 2 ,23 which was activated as its pentafluorophenyl ester 8 prior to coupling with N α ‐Fmoc‐ L ‐lysine (Scheme ). NMR examination of the crude mixture showed a triplet at δ = 6.67 ppm for the NH group of the newly formed amide bond.…”