620-84-8Relevant academic research and scientific papers
Palladium(II)-acetylacetonato complexes with mesoionic carbenes: Synthesis, structures and their application in the Suzuki-Miyaura cross coupling reaction
Hettmanczyk, Lara,Schmid, Bianca,Hohloch, Stephan,Sarkar, Biprajit
, (2016)
A series of novel palladium(II) acetylacetonato complexes bearing mesoionic carbenes (MICs) have been synthesized and characterized. The synthesis of the complexes of type (MIC)Pd(acac)I (MIC = 1-mesityl-3-methyl-4-phenyl-1,2,3-triazol-5-ylidene (1), 1,4-(2,4,6-methyl)-phenyl-3-methyl-1,2,3-triazol-5-ylidene (2), 1,4-(2,6-diisopropyl)-phenyl-3-methyl-1,2,3-triazol-5-ylidene (3); acac = acetylacetonato) via direct metalation starting from the corresponding triazolium iodides and palladium(II) acetylacetonate is described herein. All complexes were characterized by 1H- and 13C-NMR spectroscopy and high resolution mass spectrometry. Additionally, two of the complexes were characterized by single crystal X-ray crystallography confirming a square-planar coordination geometry of the palladium(II) center. A delocalized bonding situation was observed within the triazolylidene rings as well as for the acac ligand respectively. Complex 2 was found to be an efficient pre-catalyst for the Suzuki-Miyaura cross coupling reaction between aryl-bromides or -chlorides with phenylboronic acid.
Synthesis of 2-methylcarbamazepine, a new internal standard for chromatographic assays of carbamazepine (Tegretol)
Patton,Dudley
, p. 257 - 262,258,261 (1979)
The synthesis of 2-methyl-5H-dibenz[b,f]azepine-5-carboxamide (2-methylcarbamazepine, 2-MCBZ), a promising internal standard for chromatographic assays of the antiepileptic agent carbamazepine is described. N-(p-tolyl)anthranilic acid was utilized as a starting material for the synthesis of a key compound, 2,9-dimethylacridine, which was converted in two steps to 2-methyl-9-hydroxymethylacridan. The acridan, in the presence of polyphosphoric acid, was ring-expanded to form 2-methyl-5H-dibenz[b,f]azepine, this latter compound being converted by conventional reactions to its 5-carbamyl derivative, 2-MCBZ.
Synthesis of 3-aryl-2-phosphinoimidazo[1,2-: A] pyridine ligands for use in palladium-catalyzed cross-coupling reactions
Tran, Ryan Q.,Jacoby, Seth A.,Roberts, Kaitlyn E.,Swann, William A.,Harris, Nekoda W.,Dinh, Long P.,Denison, Emily L.,Yet, Larry
, p. 17778 - 17782 (2019)
3-Aryl-2-phosphinoimidazo[1,2-a]pyridine ligands were synthesized from 2-aminopyridine via two complementary routes. The first synthetic route involves the copper-catalyzed iodine-mediated cyclizations of 2-aminopyridine with arylacetylenes followed by palladium-catalyzed cross-coupling reactions with phosphines. The second synthetic route requires the preparation of 2,3-diiodoimidazo[1,2-a]pyridine or 2-iodo-3-bromoimidazo[1,2-a]pyridine from 2-aminopyridine followed by palladium-catalyzed Suzuki/phosphination or a phosphination/Suzuki cross-coupling reactions sequence, respectively. Preliminary model studies on the Suzuki synthesis of sterically-hindered biaryl and Buchwald-Hartwig amination compounds are presented with these ligands.
Investigation on the coupling reactions of aryltriflates with aromatic amines: Selection of the metal catalyst
Torisawa, Yasuhiro,Hashimoto, Akihiro,Furuta, Takuya,Minamikawa, Jun-Ichi
, p. 1821 - 1824 (1997)
A simple and effective coupling reaction of aryl triflates with aniline derivatives in the presence of palladium catalyst is described, which appears to be a general and useful protocol for the preparation of functionalized arylamines starting from phenols.
On the efficiency of two-coordinate palladium(0) N-heterocyclic carbene complexes in amination and Suzuki-Miyaura reactions of aryl chlorides
Arentsen, Katherine,Caddick, Stephen,Cloke, F. Geoffrey N.
, p. 9710 - 9715 (2005)
The catalytic activity of novel two-coordinate palladium N-heterocyclic carbene complexes that differ in their steric and electronic properties is compared in catalytic amination and Suzuki-Miyaura cross-couplings.
COMPLEXES OF N-HETEROCYCLIC CARBENES FOR TRANSITION METAL CATALYSIS
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Paragraph 34, (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.
Cu(I)–N-heterocyclic carbene-catalyzed base free C–N bond formation of arylboronic acids with amines and azoles
Zhang, Maoyuan,Xu, Zengbing,Shi, Dabin
, (2020/12/25)
A new N-heterocyclic carbene (NHC) precursor of imidazolium chloride and its corresponding Cu(I)–NHC complex 1 was synthesized. The complex 1 was found to be a highly effective catalyst for Chan-Evans-Lam coupling of arylboronic acid with amines and azoles (including imidazole, pyrazole and triazole), without addition of base at room temperature. Various substituents on three substrates can be tolerated, giving the desired coupling products in good to excellent yields (62–94%). The method is practical and offers an alternative to the corresponding copper-catalyzed Chan-Evans-Lam process for the construction of C–N bonds.
A Tetraarylpyrrole-Based Phosphine Ligand for the Palladium-Catalyzed Amination of Aryl Chlorides
Sai, Masahiro
supporting information, p. 5422 - 5428 (2021/10/08)
A tetraarylpyrrole-based phosphine ligand L1 in combination with Pd(dba)2 provided a catalyst for the Buchwald-Hartwig amination reaction. A variety of amines were rapidly coupled with aryl chlorides at a Pd loading of 0.5 mol%. The selective monoarylation of aliphatic primary amines was achieved in the presence of 0.8 equiv. water. Comparison experiments were also conducted, which revealed that the catalytic activity of L1 is superior to representative phosphine ligands in the Pd-catalyzed C?N coupling of various amines. (Figure presented.).
N-Heterocyclic Carbene Palladium(II) Amine Complexes: The Role of Primary Aryl- or Alkylamine Binding and Applications in the Buchwald-Hartwig Amination Reaction
Chen, Ming-Tsz,Hsu, Yu-Cheng
supporting information, (2021/12/24)
N-heterocyclic carbene-palladium(II) amine complexes bearing primary aryl- or alkylamines were synthesized. The prepared complexes were characterized by single crystal X-ray diffraction as well as NMR spectroscopy. These complexes exhibited good catalytic activities for the Buchwald-Hartwig amination reaction of aryl chlorides to afford arylated anilines under mild conditions. All reactions were carried out in air and all starting materials were used as supplied without purification. 21 expected coupling products were obtained in moderate to high yields under optimum conditions.
N-substituted aminobiphenyl palladacycles stabilized by dialkylterphenyl phosphanes: Preparation and applications in C[sbnd]N cross-coupling reactions
Monti, Andrea,Rama, Raquel J.,Gómez, Beatriz,Maya, Celia,álvarez, Eleuterio,Carmona, Ernesto,Nicasio, M. Carmen
supporting information, (2021/01/19)
Neutral and cationic N-methyl- and N-phenyl-2-aminobiphenyl methanesulfonate palladacycles stabilized with dialkylterphenyl phosphanes have been prepared and characterized. Neutral structures are favored with the less bulky phosphane PMe2ArXyl2, L1, while more sterically demanding ligands PiPr2ArXyl2, L3, and PCyp2ArXyl2 (Cyp = cyclopentyl), L4, lead to cationic complexes in which the phosphane exhibits a bidentate κ1-P, η1-Carene coordination mode involving one of the ipso carbon atoms of a flanking terphenyl aryl ring. The complexes were evaluated for activity in C[sbnd]N cross-coupling reactions and [Pd(N-methyl-2-aminobiphenyl)L4](OMs) (OMs = mesylate) was identified as the most efficient precatalyst, facilitating the coupling of aryl chlorides with secondary and primary amines and indoles.
