1140-16-5Relevant articles and documents
Friedel-crafts reaction of BIS(Trichloromethyl)carbonate for the preparation of benzophenones
Peng, Xiaojun,Wang, Jingyun,Cui, Jingnan,Zhang, Rong,Yan, Ying
, p. 2361 - 2367 (2002)
Benzophenones (RC6H4COC6H4R, R=H, Cl, CH3 or (CH3)2N) have been prepared by the Friedel-Crafts reactions of aromatic compounds C6H5R with bis(trichloromethy
Evaluation of Cyclic Amides as Activating Groups in N-C Bond Cross-Coupling: Discovery of N-Acyl-δ-valerolactams as Effective Twisted Amide Precursors for Cross-Coupling Reactions
Bisz, Elwira,Chen, Hao,Dziuk, B?a?ej,Ejsmont, Krzysztof,Lalancette, Roger,Pyle, Daniel J.,Rahman, Md. Mahbubur,Szostak, Michal,Szostak, Roman,Wang, Qi
, p. 10455 - 10466 (2021)
The development of efficient methods for facilitating N-C(O) bond activation in amides is an important objective in organic synthesis that permits the manipulation of the traditionally unreactive amide bonds. Herein, we report a comparative evaluation of a series of cyclic amides as activating groups in amide N-C(O) bond cross-coupling. Evaluation of N-acyl-imides, N-acyl-lactams, and N-acyl-oxazolidinones bearing five- and six-membered rings using Pd(II)-NHC and Pd-phosphine systems reveals the relative reactivity order of N-activating groups in Suzuki-Miyaura cross-coupling. The reactivity of activated phenolic esters and thioesters is evaluated for comparison in O-C(O) and S-C(O) cross-coupling under the same reaction conditions. Most notably, the study reveals N-acyl-δ-valerolactams as a highly effective class of mono-N-acyl-activated amide precursors in cross-coupling. The X-ray structure of the model N-acyl-δ-valerolactam is characterized by an additive Winkler-Dunitz distortion parameter ?(τ+χN) of 54.0°, placing this amide in a medium distortion range of twisted amides. Computational studies provide insight into the structural and energetic parameters of the amide bond, including amidic resonance, N/O-protonation aptitude, and the rotational barrier around the N-C(O) axis. This class of N-acyl-lactams will be a valuable addition to the growing portfolio of amide electrophiles for cross-coupling reactions by acyl-metal intermediates.
In situ generation of palladium nanoparticles: Ligand-free palladium catalyzed pivalic acid assisted carbonylative Suzuki reactions at ambient conditions
Zhou, Qing,Wei, Shaohua,Han, Wei
, p. 1454 - 1460 (2014)
Highly selective carbonylative Suzuki reactions of aryl iodides with arylboronic acids using an in situ generated nanopalladium system furnished products in high yields. The reactions were performed under ambient conditions and in the absence of an added ligand. The key to success is the addition of pivalic acid, which can effectively suppress undesired Suzuki coupling. The synthesis can be easily scaled up, and the catalytic system can be reused up to nine times. The nature of the active catalytic species are discussed.
Nickel-catalyzed coupling of aryl iodides with aromatic aldehydes: Chemoselective synthesis of ketones
Huang, Yi-Chun,Majumdar, Kanak Kanti,Cheng, Chien-Hong
, p. 1682 - 1684 (2002)
Aryl iodide (ArI) couple with aryl aldehydes (Ar'CHO) in the presence of Ni(dppe)Br2 and Zn to give the corresponding biaryl ketones (ArCOAr′). The use of a bidentate phosphine complex is critical to the success of this catalytic reaction. The
Suzuki-Miyaura cross-coupling of esters by selective O-C(O) cleavage mediated by air- And moisture-stable [Pd(NHC)(μ-Cl)Cl]2precatalysts: Catalyst evaluation and mechanism
Cavallo, Luigi,Nolan, Steven P.,Poater, Albert,Szostak, Michal,Yang, Shiyi,Zhou, Tongliang
, p. 3189 - 3197 (2021/05/25)
The cross-coupling of aryl esters has emerged as a powerful platform for the functionalization of otherwise inert acyl C-O bonds in chemical synthesis and catalysis. Herein, we report a combined experimental and computational study on the acyl Suzuki-Miyaura cross-coupling of aryl esters mediated by well-defined, air- and moisture-stable Pd(ii)-NHC precatalysts [Pd(NHC)(μ-Cl)Cl]2. We present a comprehensive evaluation of [Pd(NHC)(μ-Cl)Cl]2 precatalysts and compare them with the present state-of-the-art [(Pd(NHC)allyl] precatalysts bearing allyl-type throw-away ligands. Most importantly, the study reveals [Pd(NHC)(μ-Cl)Cl]2 as the most reactive precatalysts discovered to date in this reactivity manifold. The unique synthetic utility of this unconventional O-C(O) cross-coupling is highlighted in the late-stage functionalization of pharmaceuticals and sequential chemoselective cross-coupling, providing access to valuable ketone products by a catalytic mechanism involving Pd insertion into the aryl ester bond. Furthermore, we present a comprehensive study of the catalytic cycle by DFT methods. Considering the clear advantages of [Pd(NHC)(μ-Cl)Cl]2 precatalysts on several levels, including facile one-pot synthesis, superior atom-economic profile to all other Pd(ii)-NHC catalysts, and versatile reactivity, these should be considered as the 'first-choice' catalysts for all routine applications in ester O-C(O) bond activation.
Tetra- And Dinuclear Palladium Complexes Based on a Ligand of 2,8-Di-2-pyridinylanthyridine: Preparation, Characterization, and Catalytic Activity
Lin, Shih-Chieh Aaron,Liu, Shiuh-Tzung,Liu, Yi-Hung,Peng, Shie-Ming,Su, Bo-Kai
, p. 2081 - 2089 (2021/07/26)
Complexation of L [L = 5-phenyl-2,8-di-2-pyridinyl-anthyridine] with [Pd(CH3CN)4](BF4)2 and [Pd(CH3CN)3Cl](BF4) in a molar ratio of 1:2 rendered the corresponding dinuclear complexes [Pd2L (CH3CN)4](BF4)4 (1) and [Pd2L (CH3CN)2Cl2](BF4)2 (2), respectively. However, treatment of L with (COD)PdCl2 followed by anion exchange yielded a tetranuclear complex [Pd4L3Cl4](PF6)4(4a). Structures of these complexes are characterized by both spectroscopy and X-ray crystallography. Interconversion of these three complexes was studied via the manipulation of stoichiometric ratio of ligand to metal precursor. The catalytic activity of these complexes for carbonylative Suzuki-Miyaura cross-coupling was investigated. Complex 2 shows an excellent catalytic activity on the reaction of aryl iodide with arylboronic acid in the presence of atmospheric pressure of CO to give the corresponding benzophenones.
