Amide-Forming Ligation of Acyltrifluoroborates and Hydroxylamines in'Water

摘要

Amides are among the most prevalent organic functional groups, especially as components of natural products and pharmaceuticals and as the backbone of peptides. The most common means of preparing amides is the dehydrative coupling of amines with carboxylic acids, but the need to fully protect other functional groups and to employ excess amounts of coupling reagents renders it increasingly unattractive in comparison to a new generation of bond-forming reactions. Carbon-carbon bonds, for example, are now routinely prepared from prefunctionalized reagents, such as boronic acids, using operationally simple and catalytic conditions, which tolerate unprotected functional groups. Amide-forming reactions that meet these strict criteria have the potential to facilitate small-molecule drug discovery and enable chemo-selective bioconjugation reactions. Our group and others have therefore sought to identify mechanistically unique amide-forming reactions from precursors other than amines and carboxylic acids.