[reaction: see text] A new methodology for determining absolute configurations by NMR in just a few minutes is presented. The required derivatives are obtained by mixing a solid matrix-bound auxiliary reagent (MPA, MTPA, or BPG) with the chiral substrate (primary amines or secondary alcohols) directly in the NMR tube. The NMR spectra of the derivatives are obtained without any type of separation, workup, or manipulation. The use of a 1:2 (R)/(S)-MPA resin permits the configurational assignment to be carried out with just one spectrum.