Structural Analyses of
<i>N</i>
‐Acetylated 4‐(Dimethylamino)pyridine (DMAP) Salts
作者:Volker Lutz、Jörg Glatthaar、Christian Würtele、Michael Serafin、Heike Hausmann、Peter R. Schreiner
DOI:10.1002/chem.200901379
日期:2009.8.24
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
我们研究了几种N-乙酰基-4-(二甲氨基)吡啶 (DMAP) 盐(与 Cl -、CH 3 COO -和 CF 3 COO -抗衡离子)的形成,它们被认为是 DMAP 中的催化活性物质催化醇的乙酰化反应。结合晶体结构分析、变温矩阵红外和核磁共振光谱以及 UAHF-PCM-B3LYP/6-311+G(d,p)//B3LYP/6-31G(d) 水平的计算技术来检查盐形成的结构和动力学。我们发现了通过动态氢键相互作用稳定的紧密离子对形成的明确证据。在非极性溶剂中,醋酸盐的亲核性N-乙酰基-DMAP 盐在室温下仅允许稳态浓度小于 1%。因此,我们提出与醇的额外氢键相互作用是后续乙酰化的关键稳定因素。