借助含磺酰基的布朗斯台德酸离子液体,开发了一种使用容易获得的吲哚和简单的酮为底物合成3-乙烯基吲哚的直接脱水偶联方案。该协议的主要特点是合成效率高,无金属和无溶剂系统,可循环使用的催化剂,条件温和且产品易于分离。使用离子液体催化剂,还以2-羟基甲基吲哚和苯乙酮为起始原料,开发了迄今为止尚未报道的简单的吲哚[3,2- b ]咔唑骨架的构建方法。
Facile synthesis of densely substituted chroman derivatives through Brønsted acid ionic liquid catalyzed three-component reactions of aromatic aldehydes, 1,1-diarylethylenes and nucleophiles
densely substituted chroman derivatives were synthesized through hitherto unreported three-componentreactions of aromatic aldehydes, 1,1-diarylethylenes and nucleophiles. The representative reactions involve (i) condensation of benzaldehyde, 2-naphthol and 1,1-diphenylethylene and (ii) selective assembly of salicylaldehyde, indole and 1,1-diphenylethylene. The reactions were performed under solvent-free
media has emerged as a new facet of green chemistry. In this paper, a sulfone‐containing imidazolium‐based Brønsted acid ionic liquid was prepared and used as a recyclable acid catalyst. The ionic liquid catalyst enables the use of an industrially acceptable and environmentally benign solvent, butyl acetate, as the reaction medium. The ionic liquid/butyl acetate biphasic system was successfully utilized
Methyl glycolate (MG) was synthesized as a precursor to ethylene glycol from the catalytic carbonylation of formaldehyde followed by esterification with methanol by using metal-free, efficient and recyclable SO3H-functionalized ionic liquids (BAILs) as catalysts. Among the studied BAILs, N-butyl-N-(3-sulfonylpropyl) thiomorpholine-1,1-dioxide triflate showed excellent activity and MG selectivity. The effects of reaction parameters such as reactant, solvent, catalyst loading, molar ratio of H2O to H2CO, temperature, pressure, and reaction time were studied. MG was obtained in high yield under mild conditions. At 160 degrees C, 5.0 MPa, and reactant mole ratio of BAIL: H2CO:H2O = 1:40: 80, 98 % conversion of formaldehyde was achieved with 94 % selectivities of MG. Catalysts did not show any significant deterioration in performance in repeated use up to eight batches.