27347-14-4Relevant articles and documents
A novel, safe, and robust nitration process for the synthesis of 4-(4-methoxy-3-nitrophenyl)morpholine
Pingsheng, Zhang,Shankar, Ashish,Cleary, Thomas P.,Cedilote, Miall,Locklear, Dobbert,Pierce, Michael E.
, p. 861 - 864 (2007)
A novel nitration process was developed for the production of 4-(4-methoxy-3-nitrophenyl)morpholine. Crude 4-(4-methoxyphenyl-)morpholine produced in step 1 was converted to its nitric acid salt. The nitration reaction was carried out by adding a dichloro
Pd(η3-1-PhC3H4)(η5- C5H5) as a catalyst precursor for Buchwald-Hartwig amination reactions
Borjian, Sogol,Tom, David M. E.,Baird, Michael C.
, p. 3928 - 3935 (2014)
The compound Pd(η3-1-Ph-C3H4) (η5-C5H5) (I) reacts cleanly with many tertiary phosphines L to undergo reductive elimination of PhC3H 4-C5H5 and form palladium(0) species of the types PdLn (n = 2, 3), long believed to be exemplary catalysts for Suzuki-Miyaura, Heck-Mizoroki, and Sonogashira cross-coupling reactions. I has accordingly been shown to be generally much more effective for these catalytic processes than are conventional catalyst precursors such as Pd(PPh 3)4, Pd2(dba)3, PdCl2, and Pd(OAc)2, in large part because I stands alone in this series for its ability to generate specifically and efficiently the desired species PdL2 in many cases. We have now investigated I as a precursor for prototypical Buchwald-Hartwig amination reactions of 4-bromo- and 4-chloroanisole with morpholine, making comparisons with Pd2(dba) 3, Pd(OAc)2, and [Pd(η3-1-Ph-C 3H4)Cl]2 (IV). In this work we have utilized PBut3 because of its general effectiveness, and we have also assessed XPhos and Mor-Dalphos, representatives of important classes of phosphines utilized elsewhere for amination reactions.
SnCl4 and SbCl5 promoted aromatization of enamines
Bigdeli, Mohammad Ali,Rahmati, Abbas,Abbasi-Ghadim, Hossein,Mahdavinia, Gholam Hossein
, p. 4575 - 4578 (2007)
Aromatic amines have been synthesized efficiently from enamines using SnCl4 and SbCl5 in CH2Cl2 at room temperature.
Experimental and theoretical investigations of new dinuclear palladium complexes as precatalysts for the amination of aryl chlorides
Christmann, Ute,Pantazis, Dimitrios A.,Benet-Buchholz, Jordi,McGrady, John E.,Maseras, Feliu,Vilar, Ramon
, p. 6376 - 6390 (2006)
A series of new palladium dinuclear species with general formula [Pd 2X(μ-X){μ- PtBu2(Bph-R)}] (X = Cl, Br; Bph = biphenyl; R = H, Me, NMe2) have been prepared. The two palladium centers in these species are bridged by one of the aromatic rings of the biphenyl group present in the corresponding phosphine. The X-ray crystal structure of one of these complexes has been obtained, providing a clear picture of the bonding pattern. The stability of these dimers in solution is shown to be highly dependent on the nature of the phosphine R group and also on the bridging halide. When R = NMe2, the dimers dissociate, yielding the palladium(II) compounds PdX2{PtBu2(BPh-NMe 2)} (X = Cl, Br), and the X-ray crystal structure of one of them (X = Br) has shown that the biphenyl group from the phosphine interacts directly with the metal center. This interaction seems to play an important role in stabilizing the otherwise coordinatively unsaturated palladium(II) complex. In contrast, when R = H or Me, the analogous monomeric palladium(II) complexes are unstable and undergo cyclometalation to generate a palladium(II) dinuclear species in which each of the two phosphines cyclometalates with the palladium centers forming a strained four-membered ring. In addition to their unusual structures, these aryl-bridged dimers have also proven to be excellent precatalysts for the amination of aryl chlorides. To rationalize some of the experimental results, a detailed DFT computational study has been carried out and is presented herein.
A stable (amino)(phosphino)carbene as bidentate ligand for palladium and nickel complexes: Synthesis, structure, and catalytic activity
Teuma, Emmanuelle,Lyon-Saunier, Céline,Gornitzka, Heinz,Mignani, Gérard,Baceiredo, Antoine,Bertrand, Guy
, p. 5541 - 5545 (2005)
Two original complexes featuring an (amino)(phosphino)carbene η2-bonded to the metal have been obtained in 60% and 80% yields, by addition of the corresponding stable carbene to PdCl2(cod) and NiCl2(PPh3)2
A Simple Synthetic Route to Well-Defined [Pd(NHC)Cl(1-tBu-indenyl)] Pre-catalysts for Cross-Coupling Reactions
Liu, Yaxu,Scattolin, Thomas,Gobbo, Alberto,Beli?, Marek,Van Hecke, Kristof,Nolan, Steven P.,Cazin, Catherine S. J.
, (2021/12/22)
The development of robust, more efficient, general, easily accessible Pd(II)–NHC pre-catalysts remains a key issue in cross-coupling applications. A selection of well-defined, air and moisture stable [Pd(NHC)Cl(1-tBu-indenyl)] (NHC=IPr, IPrCl, IMes, SIMes, IPr*) pre-catalysts have been synthesized in good to excellent yields by reacting [Pd(1-tBu-indenyl)(μ-Cl)]2 and various NHC?HCl precursors in the presence of the weak base K2CO3 in green acetone. The synthesized Pd(II)-NHC derivatives displayed excellent catalytic activity in classical Suzuki-Miyaura and Buchwald–Hartwig reactions, especially when IPrCl is employed as ancillary ligand. Additionally, in the challenging Suzuki-Miyaura reaction between esters and arylboronic acids, the [Pd(IPr*)Cl(1-tBu-indenyl)] complex exhibited the optimum catalytic activity under very mild reaction conditions.
Electrochemical Cross-Dehydrogenative Aromatization Protocol for the Synthesis of Aromatic Amines
Tao, Shao-Kun,Chen, Shan-Yong,Feng, Mei-Lin,Xu, Jia-Qi,Yuan, Mao-Lin,Fu, Hai-Yan,Li, Rui-Xiang,Chen, Hua,Zheng, Xue-Li,Yu, Xiao-Qi
supporting information, p. 1011 - 1016 (2022/02/05)
The introduction of amines onto aromatics without metal catalysts and chemical oxidants is synthetically challenging. Herein, we report the first example of an electrochemical cross-dehydrogenative aromatization (ECDA) reaction of saturated cyclohexanones and amines to construct anilines without additional metal catalysts and chemical oxidants. This reaction exhibits a broad scope of cyclohexanones including heterocyclic ketones, affording a variety of aromatic amines with various functionalities, and shows great potential in the synthesis of biologically active compounds.
Product selective reaction controlled by the combination of palladium nanoparticles, continuous microwave irradiation, and a co-existing solid; ligand-free Buchwald-Hartwig aminationvs.aryne amination
Akiyama, Toshiki,Arai, Masayoshi,Arisawa, Mitsuhiro,Haneoka, Hitoshi,Harada, Kazuo,Murai, Kenichi,Murakami, Yosuke,Ohki, Yuuta,Ohta, Ryousuke,Sako, Makoto,Sirimangkalakitti, Natchanun,Suzuki, Takeyuki,Takahashi, Naoyuki,Takehara, Tsunayoshi,Yamada, Makito
supporting information, p. 8131 - 8137 (2021/10/29)
We have developed a continuous microwave irradiation-assisted Buchwald-Hartwig amination using our original Pd nanoparticle catalyst with a copper plate as a co-existing metal solid. In this methodology, a microwave-controlled product selectivity was achieved between Buchwald-Hartwig amination and aryne amination performed under strongly basic conditions and at a high reaction temperature, because a polar chemical species such as Ar-Pd-halogen might be activated selectively by microwave radiation. Moreover, our catalyst could be used repeatedly over 10 times, and the amount of Pd leaching could be suppressed to a low level.
COMPLEXES OF N-HETEROCYCLIC CARBENES FOR TRANSITION METAL CATALYSIS
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Paragraph 32; 35, (2021/07/17)
Described herein is a new class of highly active Pd(II)-NHC complexes bearing anilines as throw-away ligands. These catalysts are well-defined, air- and moisture-stable and can be easily purified by chromatographic techniques. High activity and generality has been exemplified in the Suzuki-Miyaura cross-coupling by C-N, C-O and C-Cl cleavage. Facile syntheses of these catalysts is also described.
IPr# - highly hindered, broadly applicable N-heterocyclic carbenes
Flach, Carol,Lalancette, Roger,Li, Guangchen,Mendelsohn, Richard,Meng, Guangrong,Szostak, Michal,Szostak, Roman,Zhao, Qun
, p. 10583 - 10589 (2021/08/20)
IPr (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) represents the most important NHC (NHC = N-heterocyclic carbene) ligand throughout the field of homogeneous catalysis. Herein, we report the synthesis, catalytic activity, and full structural and electronic characterization of novel, sterically-bulky, easily-accessible NHC ligands based on the hash peralkylation concept, including IPr#, Np# and BIAN-IPr#. The new ligands have been commercialized in collaboration with Millipore Sigma: IPr#HCl, 915653; Np#HCl; 915912; BIAN-IPr#HCl, 916420, enabling broad access of the academic and industrial researchers to new ligands for reaction optimization and screening. In particular, the synthesis of IPr# hinges upon cost-effective, modular alkylation of aniline, an industrial chemical that is available in bulk. The generality of this approach in ligand design is demonstrated through facile synthesis of BIAN-IPr# and Np#, two ligands that differ in steric properties and N-wingtip arrangement. The broad activity in various cross-coupling reactions in an array of N-C, O-C, C-Cl, C-Br, C-S and C-H bond cross-couplings is demonstrated. The evaluation of steric, electron-donating and π-accepting properties as well as coordination chemistry to Au(i), Rh(i) and Pd(ii) is presented. Given the tremendous importance of NHC ligands in homogenous catalysis, we expect that this new class of NHCs will find rapid and widespread application.
