o-acetamidophenylboronate esters stabilized toward hydrolysis by an intramolecular O-B interaction: potential linkers for selective bioconjugation via vicinal diol moieties of carbohydrates.
The synthesis and properties of o-acetamidophenylboronic acid 8 and the corresponding 1,2-diol cyclic boronates 13 and 16 are reported. The presence of an O-B interaction in 8 and 13 has been established by 11B and 1H NMR spectroscopy. The O-B interaction stabilizes boronate 13 toward hydrolysis and accelerates esterification of acid 8 in contrast to the non-ortho-substituted boronate 10 and acid 3. The enhanced stability of o-acetamidophenylboronate esters toward hydrolysis suggests their application as vicinal diol protecting groups in carbohydrate synthesis. Through the incorporation of an amino group as a second site for a coupling reaction (e.g. via isothiocyanate 22), o-acetamidophenylboronic acids may serve as novel agents for bioconjugation reactions involving carbohydrate moieties.
Cai
S X
SX
Department of Chemistry, University of Oregon, Eugene 97403.
Keana
J F
JF
D001896:Boron Compounds / Q000737:chemistry* / Q000378:metabolism; D002241:Carbohydrates / Q000737:chemistry*; D004121:Dimethyl Sulfoxide; D004355:Drug Stability; D004951:Esterification; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013329:Structure-Activity Relationship
D001896:Boron Compounds; D002241:Carbohydrates; D004121:Dimethyl Sulfoxide