Synthesis of Triarylmethanes via Palladium-Catalyzed Suzuki–Miyaura Reactions of Diarylmethyl Esters
作者:Amira H. Dardir、Irene Casademont-Reig、David Balcells、Jonathan D. Ellefsen、Matthew R. Espinosa、Nilay Hazari、Nicholas E. Smith
DOI:10.1021/acs.organomet.1c00085
日期:2021.7.26
compatible with systems for diarylmethyl ester coupling. Furthermore, the reaction can be performed stereospecifically to generate stereoinverted products. On the basis of DFT calculations, it is proposed that the oxidative addition of the diarylmethyl 2,3,4,5,6-pentafluorobenzoate substrate occurs via an SN2 pathway, which results in the inverted products. Mechanistic studies indicate that oxidative addition
NiXantphos: A Deprotonatable Ligand for Room-Temperature Palladium-Catalyzed Cross-Couplings of Aryl Chlorides
作者:Jiadi Zhang、Ana Bellomo、Nisalak Trongsiriwat、Tiezheng Jia、Patrick J. Carroll、Spencer D. Dreher、Matthew T. Tudge、Haolin Yin、Jerome R. Robinson、Eric J. Schelter、Patrick J. Walsh
DOI:10.1021/ja411855d
日期:2014.4.30
remarkable chemoselectivity in the presence of aryl chloride substrates bearing heteroaryl groups and sensitive functional groups that are known to undergo 1,2-addition, aldol reaction, and O-, N-, enolate-α-, and C(sp2)–H arylations. The advantages and importance of the Pd–NiXantphos catalyst system outlined herein make it a valuable contribution for applications in Pd-catalyzed arylationreactions with
Palladium-Catalyzed C(sp<sup>3</sup>)–H Arylation of Diarylmethanes at Room Temperature: Synthesis of Triarylmethanes via Deprotonative-Cross-Coupling Processes
作者:Jiadi Zhang、Ana Bellomo、Andrea D. Creamer、Spencer D. Dreher、Patrick J. Walsh
DOI:10.1021/ja3047816
日期:2012.8.22
this approach is an in situ metalation of the substrate via C-H deprotonation under catalytic cross-coupling conditions, which is referred to as a deprotonative-cross-coupling process (DCCP). Base and catalyst identification were performed by high-throughput experimentation (HTE) and led to a unique base/catalyst combination [KN(SiMe(3))(2)/Pd-NiXantphos] that proved to efficiently promote the room-temperature
the support. The decatungstate anions were present mainly on the silica surface without any modification, whereas these underwent a partial depolymerization on their deposition on the γ-alumina surface. The extent of depolymerization was less in the sample prepared at pH above pzc. These findings were explained in terms of the mode of deposition of the W(VI) species from the solution onto the support
通过湿法浸渍在γ表面上沉积十钨酸盐类物质W 10 O 4- 32,制备了四种钨负载量相同的负载型催化剂。-氧化铝和二氧化硅在不同的pH值。使用BET测量以及XRD,UV-vis DR和XP光谱学对制备的样品进行表征。与相应的氧化铝负载的催化剂相比,在二氧化硅负载的催化剂中获得了更高的W(VI)羰基物种的分散度。在相同的载体内,当浸渍的pH值低于载体的零电荷点(pzc)时,分散度更高。分解钨酸根阴离子主要存在于二氧化硅表面而没有任何修饰,而它们在γ上的沉积过程中发生了部分解聚。-氧化铝表面。在高于pzc的pH值下制备的样品中,解聚程度较小。这些发现是根据W(VI)物种从溶液到支持物表面的沉积方式进行解释的。上述催化剂的光催化活性,关于1-苯基乙醇的光氧化,依赖于W的分数10个ö 4- 32支持物种,而不是在W(VI)分散体。因此,在基于二氧化硅的催化剂上以及在γ上均获得了极高的转化率。-在较
Modular Synthesis of Triarylmethanes through Palladium-Catalyzed Sequential Arylation of Methyl Phenyl Sulfone
作者:Masakazu Nambo、Cathleen M. Crudden
DOI:10.1002/anie.201307019
日期:2014.1.13
Triarylmethanes, which are valuable structures in materials, sensing and pharmaceuticals, have been synthesized starting from methylphenylsulfone as an inexpensive and readily available template. The three aryl groups were installed through two sequential palladium‐catalyzed CH arylation reactions, followed by an arylative desulfonation. This method provides a new synthetic approach to multisubstituted