Journal article

Publication year: 2009

Pages: 8548-8557

Journal: Chemistry - A European Journal

Volume number: 15

Issue number: 34

DOI Link: https://doi.org/10.1002/chem.200901379

Publisher: Wiley

Abstract: 

We have studied the formation of several N‐acetyl‐4‐(dimethylamino)pyridine (DMAP) salts (with Cl⁻, CH₃COO⁻, and CF₃COO⁻
counterions), which are considered to be the catalytically active
species in DMAP‐catalyzed acetylation reactions of alcohols. Combined
crystal structure analyses, variable temperature matrix IR and NMR
spectroscopy as well as computational techniques at the
UAHF‐PCM‐B3LYP/6‐311+G(d,p)//B3LYP/6‐31G(d) level were utilized to
examine the structures and dynamics of salt formation. We found clear
evidence for the formation of tight ion pairs that are stabilized by
dynamic hydrogen‐bonding interactions. In nonpolar solvents, the
nucleophilicity of acetate in its N‐acetyl‐DMAP salt only allows a
steady‐state concentration smaller 1 % at room temperature. Thus, we
propose additional hydrogen‐bonding interactions with alcohols to be the
key stabilization factor in subsequent acetylations.

Harvard Citation style: Lutz, V., Glatthaar, J., Würtele, C., Serafin, M., Hausmann, H. and Schreiner, P. (2009) Structural Analyses of N‐Acetylated 4‐(Dimethylamino)pyridine (DMAP) Salts, Chemistry - A European Journal, 15(34), pp. 8548-8557. https://doi.org/10.1002/chem.200901379

APA Citation style: Lutz, V., Glatthaar, J., Würtele, C., Serafin, M., Hausmann, H., & Schreiner, P. (2009). Structural Analyses of N‐Acetylated 4‐(Dimethylamino)pyridine (DMAP) Salts. Chemistry - A European Journal. 15(34), 8548-8557. https://doi.org/10.1002/chem.200901379