本文描述了在温和的反应条件下,在较短的反应时间内,钯(0)催化Ullmann型交叉偶联反应进行芳基卤化物的N-芳基化和O-芳基化的有效方法。合成了两个硫化膦配体及其相应的Pd(0)络合物,即[Pd(p 2 S 2)(dba)]和[Pd(pp 3 S 4)(dba)],其中p 2 S 2为1, 2-双(二苯基膦基)乙烷二硫化物,pp 3 S 4是三[2-(二苯基膦基)乙基]膦四硫化物,dba是二亚苄基丙酮。通过改变温度,溶剂,碱和催化剂的负载量,确定了使用碘代苯和苯并咪唑进行芳基化反应的最佳反应条件。使用碘代苯/溴苯和具有不同空间和电子性质的各种取代的芳基胺/苯酚/醇进行交叉偶联反应,从而以良好或优异的收率得到所需的N-芳基胺/二芳基醚/烷基芳基醚( 70–94%)。
several pinacol or neopentylglycol boronates indicated further potential of the catalyst. The reaction conditions tolerate the hydroxyl and bromo functional groups. The catalytic system also enables to synthesize the mono-N-substituted anilines from primary aliphatic amines. However, the two model compounds for the secondary and aromatic amines, piperidine and aniline, do not react. Two sterically demanding
基于Chan-Lam交叉偶联反应,开发了一种基于使用稳定铜(I)源的现成Cu 2 S / TMEDA系统的催化剂。用1 H-苯并[ d ]咪唑-2(3 H)-1,1 H-苯并[ d ]咪唑和1 H-咪唑以及缺电子,富电子和在室温下,在大气氧的存在下,对空间需求量高的硼酸,以中等至极好的收率得到交叉偶联的产物。另外,1 H-苯并[ d]的偶联反应]咪唑与几种频哪醇或新戊二醇硼酸酯表明该催化剂的进一步潜力。反应条件容许羟基和溴官能团。该催化体系还能够由伯脂族胺合成单-N-取代的苯胺。但是,仲胺和芳族胺的两种模型化合物哌啶和苯胺不会反应。两个空间要求的产品与受限Ç N键的旋转,通过将合成的Ñ 1的-arylation ħ -苯并[ d ]咪唑-2(3 H ^) -酮与ö-甲苯磺酸,能够确认由Chan-Lam交叉偶联反应制得的阻转异构体。此外,已经报道了一锅Chan-Lam和Suzuki-Miyaura反应的例子。
Barbier-Negishi Coupling of Secondary Alkyl Bromides with Aryl and Alkenyl Triflates and Nonaflates
secondary alkylbromides with aryl and alkenyl triflates and nonaflates has been developed. This challenging reaction was enabled by the use of a very bulky imidazole‐based phosphine ligand, which resulted in good yields as well as good chemo‐ and site selectivities for a broad range of substrates at room temperature and under non‐aqueous conditions. This reaction was extended to primary alkyl bromides
Three imidazoliumsalts based on a rigid resorcinarene platform (1–3) were synthesised and used as catalyst precursors in the Suzuki–Miyaura cross‐coupling of aryl halides with phenylboronic acid. In these pro‐carbene ligands, the heterocyclic moiety has one N atom connected to a C2 atom of a resorcinolic ring, and the other is substituted by an alkyl group (R=n‐propyl, iso‐propyl, benzyl). The methinic
esorcin[4]arenyl substituent, the other with two, have been used as pro‐ligands (LH) for the synthesis of nickel half‐sandwich complexes of the type [NiCpClL] (Cp = cyclopentadienyl). NMR and X‐ray structural investigations revealed that in both complexes the NiCp moiety is positioned at the wider entrance of the resorcinarenyl cavity, this location providing high steric encumbrance around the metal
两个咪唑鎓盐,一用一单个Ñ -μ 4 -tetramethylenedioxyresorcin [4]烷芳基取代基,另外两个,已被用作亲配体(LH)的类型的镍半夹心络合物的合成[NiCpClL] (Cp =环戊二烯基)。NMR和X射线结构研究表明,在这两种配合物中,NiCp部分均位于间苯二甲烯基空腔的较宽入口处,该位置在金属中心周围具有很高的空间位阻。两种配合物一旦被NaBH 4活化,均能催化乙烯的二聚反应,活性最高[555 mol(C 2 H 4)mol(Ni)–1 h –1观察到带有两个cavitand取代基的配合物。
Air-stable palladium(0) phosphine sulfide catalysts for Ullmann-type C–N and C–O coupling reactions
N-arylation and O-arylation of aryl halides by Ullmann-type cross coupling reaction under mild reaction conditions in a short reaction time. Two phosphine sulphide ligands and their corresponding Pd(0) complexes namely [Pd(p2S2)(dba)] and [Pd(pp3S4)(dba)], were synthesized, where p2S2 is 1,2-bis(diphenylphosphino)ethane disulfide, pp3S4 is tris[2-(diphenylphosphino)ethyl]phosphine tetrasulfide and dba
本文描述了在温和的反应条件下,在较短的反应时间内,钯(0)催化Ullmann型交叉偶联反应进行芳基卤化物的N-芳基化和O-芳基化的有效方法。合成了两个硫化膦配体及其相应的Pd(0)络合物,即[Pd(p 2 S 2)(dba)]和[Pd(pp 3 S 4)(dba)],其中p 2 S 2为1, 2-双(二苯基膦基)乙烷二硫化物,pp 3 S 4是三[2-(二苯基膦基)乙基]膦四硫化物,dba是二亚苄基丙酮。通过改变温度,溶剂,碱和催化剂的负载量,确定了使用碘代苯和苯并咪唑进行芳基化反应的最佳反应条件。使用碘代苯/溴苯和具有不同空间和电子性质的各种取代的芳基胺/苯酚/醇进行交叉偶联反应,从而以良好或优异的收率得到所需的N-芳基胺/二芳基醚/烷基芳基醚( 70–94%)。