Pd-Catalyzed Carbonylative α-Arylation of Aryl Bromides: Scope and Mechanistic Studies
作者:Dennis U. Nielsen、Camille Lescot、Thomas M. Gøgsig、Anders T. Lindhardt、Troels Skrydstrup
DOI:10.1002/chem.201303384
日期:2013.12.23
Reaction conditions for the three‐component synthesis of aryl 1,3‐diketones are reported applying the palladium‐catalyzed carbonylative α‐arylation of ketones with aryl bromides. The optimal conditions were found by using a catalytic system derived from [Pd(dba)2] (dba=dibenzylideneacetone) as the palladium source and 1,3‐bis(diphenylphosphino)propane (DPPP) as the bidentate ligand. These transformations
据报道,使用钯催化的酮与芳基溴化物的羰基化α-芳基化反应,可以合成芳基1,3-二酮的三组分反应条件。通过使用衍生自[Pd(dba)2 ](dba =二亚苄基丙酮)作为钯源和1,3-双(二苯基膦基)丙烷(DPPP)作为二齿配体的催化体系找到了最佳条件。这些转化是在两室反应器COware中进行的,仅应用了从CO释放化合物9-甲基芴-9-羰基氯(COgen)产生的1.5当量的一氧化碳。该方法论证明可适用于多种芳基和杂芳基溴化物,从而导致多种芳基1,3-二酮。依靠31 P和进行13 C NMR光谱分析以确定可能的催化途径。我们的结果表明,[Pd(dba)2 ]和DPPP的组合仅在存在苯乙酮烯醇钠的情况下才对4-溴苯甲醚具有反应性,这表明[Pd(dppp)(enolate)]阴离子是在生成苯丙酮之前最初生成的。氧化加成步骤。随后将CO插入[Pd(Ar)(dppp)(烯酸酯)]物种中,提供了1,3-二
Photoinduced Palladium-Catalyzed Carbofunctionalization of Conjugated Dienes Proceeding via Radical-Polar Crossover Scenario: 1,2-Aminoalkylation and Beyond
作者:Kelvin Pak Shing Cheung、Daria Kurandina、Tetsuji Yata、Vladimir Gevorgyan
DOI:10.1021/jacs.0c03993
日期:2020.6.3
A photoinduced palladium-catalyzed 1,2-carbofunctionalization of conjugateddienes has been developed. This mild modular approach, which does not require employment of exogeneous photosensitizers and external oxidants, allows for efficient and highly regio- and ste-reoselective synthesis of a broad range of allylic amines from readily available 1,3-dienes, alkyl iodides, and amines. Employment of O-
A Remarkable<i>cis</i>- and<i>trans</i>-Spanning Dibenzylidene Acetone Diphosphine Chelating Ligand (dbaphos)
作者:Amanda G. Jarvis、Petr E. Sehnal、Somia E. Bajwa、Adrian C. Whitwood、Xiangbiao Zhang、Man Sing Cheung、Zhenyang Lin、Ian J. S. Fairlamb
DOI:10.1002/chem.201203691
日期:2013.5.3
A multidentate and flexible diolefin–diphosphine ligand, based on the dibenzylideneacetone core, namely dbaphos (1), is reported herein. The ligand adopts an array of different geometries at Pt, Pd and Rh. At PtII the dbaphosligand forms cis‐ and trans‐diphosphine complexes and can be defined as a wide‐angle spanning ligand. 1H NMR spectroscopic analysis shows that the β‐hydrogen of one olefin moiety
Pd(η<sup>3</sup>-1-PhC<sub>3</sub>H<sub>4</sub>)(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>), an Unusually Effective Catalyst Precursor for Heck–Mizoroki and Sonogashira Cross-Coupling Reactions Catalyzed by Bis-Phosphine Palladium(0) Compounds
作者:Andrew W. Fraser、Bryan E. Jaksic、Rhys Batcup、Christopher D. Sarsons、Michael Woolman、Michael C. Baird
DOI:10.1021/om301081r
日期:2013.1.14
apply also to e.g. Heck-Mizoroki and Sonogashira cross-coupling reactions, both of which are generally believed to be catalyzed by species of the type PdL2. Therefore, comparisons of the efficacies of catalyst systems based on Pd(η3-1-PhC3H4)(η5-C5H5), Pd(PPh3)4, Pd2(dba)3, and Pd(OAc)2 are made utilizing the conventional coupling reactions of aryl halides with methyl acrylate and styrene for Heck–Mizoroki
The partial dehydrogenation of aluminium dihydrides
作者:Thomas N. Hooper、Samantha Lau、Wenyi Chen、Ryan K. Brown、Martí Garçon、Karen Luong、Nathan S. Barrow、Andrew S. Tatton、George A. Sackman、Christopher Richardson、Andrew J. P. White、Richard I. Cooper、Alison J. Edwards、Ian J. Casely、Mark R. Crimmin
DOI:10.1039/c9sc02750e
日期:——
cyclopentadienyl complexes is reported. In the case of ruthenium, alane coordination occurs with no evidence for hydrogen loss resulting in the formation of ruthenium complexes with a pseudo–octahedral geometry and cis-relation of phosphine ligands. These new ruthenium complexes have been characterised by multinuclear and variable temperature NMRspectroscopy, IR spectroscopy and singlecrystalX-ray diffraction
报道了一系列β-二酮亚胺稳定的二氢化铝与双(膦)钌、双(膦)钯和环戊二烯钯配合物的反应。在钌的情况下,发生铝烷配位,没有氢损失的证据,导致形成具有伪八面体几何形状和顺式的钌配合物-膦配体的关系。这些新的钌配合物已通过多核和变温 NMR 光谱、IR 光谱和单晶 X 射线衍射进行了表征。在钯的情况下,一系列铝烷脱氢的结构快照已被分离和晶体学表征。铝上钯前体和配体的变化允许对含有新 Pd-Al 和 Pd-Pd 相互作用的金属间络合物的反应性和分离进行动力学控制。这些配合物的不同之处在于 H : Al (2 : 1、1.5 : 1 和 1 : 1) 的比例,其中较低的氢化物含量物质会形成二氢损失。X 射线和中子衍射研究的组合已被用于询问结构,并为确定氢化物配体的数量和位置提供信心。27 Al MAS NMR 光谱和计算 (DFT, QTAIM) 已用于了解脱氢过程。后者为脱氢伴随着金属-金属键的形成和由于新的金属-金属键的共价性导致的