Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry & Chemical Engineering, Huazhong University of Science & Technology, Luoyu Road 1037, Wuhan 430074, PR China.
Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Huazhong University of Science & Technology, Luoyu Road 1037, Wuhan 430074, PR China.
J Org Chem. 2020 Mar 6;85(5):3307-3319. doi: 10.1021/acs.joc.9b03128. Epub 2020 Jan 27.
A catalytic amount of FeCl combined with benzoyl trifluoroacetone (Hbtfa) (FeCl/Hbtfa = 1/2) was used to catalyze sulfonylation/acylation of diols and polyols using diisopropylethylamine (DIPEA) or potassium carbonate (KCO) as a base. The catalytic system exhibited high catalytic activity, leading to excellent isolated yields of sulfonylation/acylation products with high regioselectivities. Mechanism studies indicated that FeCl initially formed [Fe(btfa)] (btfa = benzoyl trifluoroacetonate) with twice the amount of Hbtfa under basic conditions in the solvent acetonitrile at room temperature. Then, Fe(btfa) and two hydroxyl groups of the substrates formed a five- or six-membered ring intermediate in the presence of the base. The subsequent reaction between the cyclic intermediate and a sulfonylation reagent led to the selective sulfonylation of the substrate. All key intermediates were captured in the high-resolution mass spectrometry assay, therefore demonstrating this mechanism for the first time.
使用催化量的 FeCl 与苯甲酰三氟丙酮（Hbtfa）（FeCl/Hbtfa = 1/2）组合，使用二异丙基乙胺（DIPEA）或碳酸钾（KCO）作为碱，催化二醇和多元醇的磺酰化/酰化反应。该催化体系表现出高催化活性，导致磺酰化/酰化产物具有高区域选择性的优异分离产率。机理研究表明，FeCl 在室温下在溶剂乙腈中，在碱性条件下首先与两倍量的 Hbtfa 形成 [Fe(btfa)]（btfa = 苯甲酰三氟乙酰酸盐）。然后，在碱的存在下，Fe(btfa)和底物的两个羟基形成一个五元或六元环中间体。随后，环状中间体与磺酰化试剂之间的反应导致底物的选择性磺酰化。所有关键中间体都在高分辨率质谱测定中被捕获，因此首次证明了这种机制。
