担载液相催化剂的研究Ⅶ．乙烯羰化制丙醛的宏观动力学

担载液相催化剂的研究Ⅶ．乙烯羰化制丙醛的宏观动力学①胡斌孙懿张红平刘省明殷元骐②（中国科学院兰州化学物理研究所，兰州７３００００）关键词羰基化乙烯丙醛固定化催化剂动力学丙醛的生产方法有多种，工业上主要应用羰基合成法．在５０年代以前，以羰基钴作催化剂，...     

Palladium-catalyzed carbonylation of aryl bromides using microwave heating and bis[CP-Fe(II)-(CO)2] as a carbon monoxide source

A palladium-catalyzed, microwave assisted carbonylative reaction is described for the synthesis of benzamides from aryl bromides and primary or secondary amines. The developed method uses bis(cyclopentadienyldicarbonyliron) as a solid source of carbon monoxide to produce a diverse set of secondary and tertiary amides in 42–82% yield.     

Oxycarbonylation of methanol over modified CuY: Enhanced activity by improving accessibility of active sites

To improve the accessibility of Cu⁺ species located in the small cages, Y zeolite was post-treated with NH₄F solution etching. The small cages were opened effectively, which allowed the reactants to interact with more Cu⁺ sites. As a result, an enhanced activity was obtained over modified CuY catalyst in oxidative carbonylation of methanol.     

High-pressure NMR study of migratory CO-insertion in palladium-methyl complexes modified with Cs-symmetrical 1,4-diphosphines

Carbonylation of the palladium complexes [PdCH₃(P^∧P′)Cl] (P^∧P′ = 1a, 1b, 1c, 1d, 1e) and [PdCH₃(P^∧P′)(CH₃CN)](OTf) was investigated by means of high-pressure NMR with the determination of the half-life times t_1/2. The results were rationalized on the basis of the electronic properties of the diphosphines and the nature of the solvento ligand in the first coordination sphere. The crystal structures of the complexes [Pd(1b)Cl₂] and [Pd(1b)(H₂O)₂](OTf)₂ are described (1b = 1-(diphenylphosphinomethyl)-2-[bis(3- trifluoromethylphenyl)phosphinomethyl]benzene).     

负载离子液体纳米钯催化芳卤羰化反应

研究了高分散性的负载离子液体纳米钯催化剂的制备及其催化芳卤羰化反应的性能. 用XRD、HRTEM和XPS等方法对催化剂进行了表征, 结果表明, 钯组分处于高分散零价态, 其平均粒径小于5 nm, 且催化剂表面存在一厚度适中的离子液体液膜, 有利于提高催化剂的稳定性; 该催化剂对PhI、PhBr、PhCl的羰化反应的催化活性优于离子液体两相催化体系, 在优化的反应条件下, 碘苯的转化率可达99.3％, 生成苯甲酸乙酯的转化频率(TOF)可高达4926 h−1, 反应产物中苯甲酸乙酯的选择性大于99％.     

Rhodium(I) carbonyl complexes of chalcogen functionalized tripodal phosphines, [CH3C(CH2P(X)Ph2)3] {X = O, S, Se} and their reactivity

The reaction of dimeric rhodium precursor [Rh(CO)₂Cl]₂ with two molar equivalent of 1,1,1-tris(diphenylphosphinomethyl)ethane trichalcogenide ligands, [CH₃C(CH₂P(X)Ph₂)₃](L), where X = O(a), S(b) and Se(c) affords the complexes of the type [Rh(CO)₂Cl(L)] (1a–1c). The complexes 1a–1c have been characterized by elemental analyses, mass spectrometry, IR and NMR (¹H, ³¹P and ¹³C) spectroscopy and the ligands a–c are structurally determined by single crystal X-ray diffraction. 1a–1c undergo oxidative addition (OA) reactions with different electrophiles such as CH₃I, C₂H₅I and C₆H₅CH₂Cl to give Rh(III) complexes of the types [Rh(CO)(COR)ClXL] {R = –CH₃ (2a–2c), –C₂H₅ (3a–3c); X = I and R = –CH₂C₆H₅ (4a–4c); X = Cl}. Kinetic data for the reaction of a–c with CH₃I indicate a first-order reaction. The catalytic activity of 1a–1c for the carbonylation of methanol to acetic acid and its ester is evaluated and a higher turn over number (TON = 1564–1723) is obtained compared to that of the well-known commercial species [Rh(CO)₂I₂]⁻ (TON = 1000) under the reaction conditions: temperature 130 ± 2 °C, pressure 30 ± 2 bar and time 1 h.     

Iminophosphine-palladium(0) complexes as catalysts in the alkoxycarbonylation of terminal alkynes

In the presence of methanesulfonic acid, the palladium(0)-olefin complexes: [Pd(η²-ol)(P---N)] [ol=dimethyl fumarate or fumaronitrile, P---N=1-(Ph₂P)C₆H₄-2-CH=NR (R=CMe₃ or C₆H₄OMe-4)] catalyse the alkoxycarbonylation of terminal alkynes. Moderately good rates are obtained when the catalysts are promoted with two equivalents of the free P---N ligand and a large excess of acid at 120°C. The catalytic data suggest that derivatives of the type [Pd(alkyne)(P---N)_n] (n=2–3) are the active catalytic species.     

Three-component coupling approach toward the synthesis of a resorcylic acid lactone framework

A resorcylic acid lactone (RAL) framework was constructed based on a three-component coupling approach. The key step was the intermolecular alkylation of a protected cyanohydrin with an aromatic scaffold, and the subsequent carbonylative esterification of the aryl iodide with an alcohol. This sequence allowed the rapid assembly of three components without extra protection/deprotection steps. This synthetic strategy enables the ketone at the 2′ position to be masked as a protected cyanohydrin during the ester formation, thus avoiding an undesired isocoumarin formation. This method should be widely applicable to the synthesis of various types of RAL frameworks.     

Pd/C: an efficient, heterogeneous and reusable catalyst for carbon monoxide-free aminocarbonylation of aryl iodides

Carbon monoxide-free aminocarbonylation is carried out efficiently via coupling of N,N-dimethylformamide (DMF) with aryl iodides using Pd/C as a heterogeneous catalyst. The catalyst exhibits remarkable activity and is reusable for up to three consecutive cycles. The reaction is applicable to a wide variety of substituted aryl iodides with different steric and electronic properties providing excellent yields of the corresponding tertiary amides.     

硒催化羰基化合成氯苯胺灵

本文报道了一种绿色且简易的合成氯苯胺灵的方法。以廉价易得且能循环使用的非金属硒作催化剂,以一氧化碳替代剧毒光气作羰基化试剂,通过异丙醇和间氯硝基苯经"一锅法"硒催化氧化还原羰基化反应直接合成氯苯胺灵。催化剂硒的反应过程相转移催化作用使其可回收循环使用。并提出了可能的反应机理。