结合富马酸酯和CO配体的环戊二烯钴复合物(见图)有效地催化炔烃,腈和/或烯烃的分子间和分子内[2 + 2 + 2]环加成反应,从而生成苯,吡啶或1,3-环己二烯。与[CpCo(CO)2 ]或[CpCo(C 2 H 4)2 ](Cp = C 5 H 5)等催化剂不同,它们具有空气稳定性,易于处理,与微波条件兼容,并且不一定需要辐射才能活跃。
结合富马酸酯和CO配体的环戊二烯钴复合物(见图)有效地催化炔烃,腈和/或烯烃的分子间和分子内[2 + 2 + 2]环加成反应,从而生成苯,吡啶或1,3-环己二烯。与[CpCo(CO)2 ]或[CpCo(C 2 H 4)2 ](Cp = C 5 H 5)等催化剂不同,它们具有空气稳定性,易于处理,与微波条件兼容,并且不一定需要辐射才能活跃。
see text] A 2-(2,6-diisopropylphenyl)iminomethylpyridine (1a)/CoCl(2).6H(2)O/Zn reagent has been developed as an effective instant catalyst for the intra- and intermolecular cyclotrimerization of alkynes to substituted benzenes, making the method extremely practical since the reagent, 1a/CoCl(2).6H(2)O/Zn, is inexpensive and easy to handle and the reaction is less sensitive to moisture and is reasonably
The ubiquitary Co(I) complex CoCl(PPh3)3 was found to be a convenient catalyst for the [2 + 2 + 2] cycloaddition of functionalized triynes under mild reaction conditions and devoid of any additional additive, yielding the substituted arene compounds. Successful development of synthetic routes to various triynes and the subsequent cyclotrimerization key step gave systematic access to a variety of different
Synthesis of Group 9 Metal-Olefin Complexes with Identical Ligand Frameworks and Comparison of their Catalytic Activity in [2+2+2] Cycloaddition and other Addition Reactions
The preparation and catalytic evaluation of the three group 9 (cyclopentadienyl)metal(trimethylvinylsilane) complexes of the type C5H5M(H2CCHSiMe3)2 (M=cobalt, rhodium and iridium) are reported. The complexes were investigated in [2+2+2] cycloaddition as well as in hydrogenation, hydroformylation and hydroboration reactions. Despite the identical organic frameworks and structural parameters, the complexes
their reactivity in [2+2+2] cycloaddition reactions compared with highly active [CpCo(H2CCHSiMe3)2] (1). Whereas 1 is an excellent precursor for the synthesis of [CpCo(olefin)(phosphite)] complexes (2 a–f), [CpCo(phosphite)2] complexes (3 a–e) were prepared photochemically from [CpCo(cod)]. The complexes were evaluated in the cyclotrimerization reaction of diynes with nitriles yielding pyridines. For
Air-Stable CpCo<sup>I</sup>
-Phosphite-Fumarate Precatalyst in Cyclization Reactions: Comparing Different Methods of Energy Supply
作者:Fabian Fischer、Marko Hapke
DOI:10.1002/ejoc.201800196
日期:2018.6.29
reactor proved to be the most time‐efficient way to rapidly assemble the expected reaction products; however, careful selection of reaction conditions can be required. The synthesis of pyridines and isoquinolines successfully involved the utilization of versatile functionalized nitriles, affording structurally interesting reaction products. Comparison with the known and often applied precatalyst CpCo(CO)2
研究了稳健的 CoI 预催化剂 [CpCo(POEt}3)(trans-MeO2CHC=CHCO2Me)] 在环三聚反应中的应用,从三炔、二炔和腈生成苯和吡啶,比较不同供能方式的影响;即辐射和常规(热)或微波加热。发现预催化剂在所有条件下都起作用,包括在室温下、在光化学条件下、在较长反应时间下催化环三聚的可能性。微波反应器中的反应被证明是快速组装预期反应产物最省时的方法;然而,可能需要仔细选择反应条件。吡啶和异喹啉的合成成功地涉及多功能官能化腈的利用,提供了结构有趣的反应产物。与已知且经常应用的预催化剂 CpCo(CO)2 进行比较,表明 CpCoI-亚磷酸酯-烯烃预催化剂具有显着更高的反应活性。