A novel 4-aminoantipyrine-Pd(II) complex catalyzes Suzuki–Miyaura cross-coupling reactions of aryl halides

• Claudia A. Contreras-Celedón,
• Darío Mendoza-Rayo,
• José A. Rincón-Medina and
• Luis Chacón-García

Beilstein J. Org. Chem. 2014, 10, 2821–2826, doi:10.3762/bjoc.10.299

• efficient. Conclusion In summary, we have developed a mild, efficient and comparatively inexpensive methodology for the synthesis of biaryl compounds. This methodology uses our newly developed 4-AAP–Pd(II) complex as a highly efficient precatalyst and general catalyst for the SM cross-coupling, works

• conditions for relatively short reaction times to afford biaryl compounds in good to excellent yields. The synthetic accessibility and stability under cross-coupling reaction conditions of 4-AAP–Pd(II) make this complex a very promising precatalyst, and we will continue studying its applicability in various

P(O)R₂-directed Pd-catalyzed C–H functionalization of biaryl derivatives to synthesize chiral phosphorous ligands

• Rong-Bin Hu,
• Hong-Li Wang,
• Hong-Yu Zhang,
• Heng Zhang,
• Yan-Na Ma and
• Shang-dong Yang

Beilstein J. Org. Chem. 2014, 10, 2071–2076, doi:10.3762/bjoc.10.215

• group not only achieved the directing role but also acts as an important component unit of the C–H functionalized products. In this paper, we use the axially chiral biaryl phosphine oxides as substrates and report the synthesis of various chiral phosphorus ligands with high enantiomeric selectivity

• reported operation, the substrates of biaryl derivatives that contained phosphate with axial chirality were obtained in high yields using the Suzuki–Miyaura coupling reaction with the assistance of this versatile chiral ligand [31][32][33][34]. We used substituted naphthylboronic acid or ortho-substituted

• system of P(O)R2-directed Pd-catalyzed C–H activation. These compounds could be transformed to trivalent phosphorus compounds by silane to obtain the corresponding phosphorous ligands. Conclusion In summary, a series of substrates with axially chiral biaryl compounds containing a P(O)Ar2 directing group

Atherton–Todd reaction: mechanism, scope and applications

• Stéphanie S. Le Corre,
• Mathieu Berchel,
• Hélène Couthon-Gourvès,
• Jean-Pierre Haelters and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2014, 10, 1166–1196, doi:10.3762/bjoc.10.117

Palladium-catalysed cross-coupling reaction of ultra-stabilised 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole compounds with aryl bromides: A direct protocol for the preparation of unsymmetrical biaryls

• Siphamandla Sithebe and
• Ross S. Robinson

Beilstein J. Org. Chem. 2014, 10, 1107–1113, doi:10.3762/bjoc.10.109

• , electron-neutral and electron-donating substituents are reacted under the catalytic system furnishing unsymmetrical biaryl products in isolated yields of up to 96% in only 10 minutes. Keywords: aryl bromide; 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole; asymmetrical biaryls; microwave; Suzuki–Miyaura

Preparation of phosphines through C–P bond formation

• Iris Wauters,
• Wouter Debrouwer and
• Christian V. Stevens

Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106

• triarylphosphines 105a as phosphinating agents. This aryl–aryl exchange reaction was compatible with several functional groups such as ketones, aldehydes, esters, nitriles, ethers (Table 11) [192][193][194][195]. Products 106a were isolated in only moderate yields. Several P,N-biaryl ligands were prepared from the

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

• Gijs Koopmanschap,
• Eelco Ruijter and
• Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

A new manganese-mediated, cobalt-catalyzed three-component synthesis of (diarylmethyl)sulfonamides

• Antoine Pignon,
• Erwan Le Gall and
• Thierry Martens

Beilstein J. Org. Chem. 2014, 10, 425–431, doi:10.3762/bjoc.10.39

• presented in Table 2. Results indicated a rather broad functional tolerance of the reaction, although some yields are limited and might be likely improved under more specific conditions. In all cases, the organic bromide was completely consumed and the main side-products were the imine and the biaryl. The

• imine results from the reaction of the tosylamide with the aldehyde, and the biaryl was formed by reductive coupling of the starting halide. A preformed imine can be used in the process (Table 2, entry 3, result in brackets), indicating that this species might be the reactive electrophilic intermediate

Recent advances in transition metal-catalyzed Csp²-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

• Grégory Landelle,
• Armen Panossian,
• Sergiy Pazenok,
• Jean-Pierre Vors and
• Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

• 2-phenylpyridine in the presence of palladium(II) catalysts (10 mol %) and starting either from 6H-perfluorohexyl bromide or perfluoroheptanoic acid [71]. Interestingly, the latter reagent provided the highest yields, and the reaction appeared to proceed through an intermediate biaryl

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

• ), muscimol (2.40), THPO (2.41) or exo-THPO (2.42, Figure 5) are potent inhibitors of GABA receptors, however, their hydrophilic nature meant that they did not cross the lipophilic blood-brain barrier. Therefore additional non-polar biaryl-appendages have been attached to these motifs separated by a short

Gold-catalyzed reaction of oxabicyclic alkenes with electron-deficient terminal alkynes to produce acrylate derivatives

• Yin-wei Sun,
• Qin Xu and
• Min Shi

Beilstein J. Org. Chem. 2013, 9, 1969–1976, doi:10.3762/bjoc.9.233

• phosphine ligand was used as a catalyst (Table 1, entry 7). In order to further improve the yield of 3a, we employed gold complex 6 (Figure 1) coordinated by a sterically bulky and electron-rich biaryl phosphine-type ligand as a catalyst, affording 3a in 40% yield (Table 1, entry 8). In the absence of

Photoinduced synthesis of unsymmetrical diaryl selenides from triarylbismuthines and diaryl diselenides

• Yohsuke Kobiki,
• Shin-ichi Kawaguchi,
• Takashi Ohe and
• Akiya Ogawa

Beilstein J. Org. Chem. 2013, 9, 1141–1147, doi:10.3762/bjoc.9.127

• this solid is a bismuth residue, which can consist of bismuth oxides and/or bismuth selenides. Moreover, it may form biaryls (Ar–Ar) as byproducts, but no biaryl was observed after the reaction. Conclusion We have found that the photoinduced reaction of diaryl diselenides with triarylbismuthines

Synthesis of phenanthridines via palladium-catalyzed picolinamide-directed sequential C–H functionalization

• Ryan Pearson,
• Shuyu Zhang,
• Gang He,
• Nicola Edwards and
• Gong Chen

Beilstein J. Org. Chem. 2013, 9, 891–899, doi:10.3762/bjoc.9.102

• bond of benzylpicolinamides is first arylated with an aryl iodide. The resulting biaryl compound is then subjected to palladium-catalyzed picolinamide-directed intramolecular dehydrogenative C–H amination with PhI(OAc)2 oxidant to form the corresponding cyclized dihydrophenanthridines. The benzylic

• with results on the Pd-catalyzed PA-directed arylation of more inert C(sp3)−H bonds [29]. Cyclization of biaryl compounds to form dihydrophenanthridines. Next, we investigated the cyclization of biaryl compounds to form dihydrophenanthridines via Pd-catalyzed intramolecular dehydrogenative amination of

Synthesis and testing of the first azobenzene mannobioside as photoswitchable ligand for the bacterial lectin FimH

• Vijayanand Chandrasekaran,
• Katharina Kolbe,
• Femke Beiroth and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2013, 9, 223–233, doi:10.3762/bjoc.9.26

• of the mannobioside is important both to mediate hydrophilicity and to intensify the steric effect that photoswitching has on the exposition of the terminal mannoside. Conclusion The azobenzene mannosides presented herein resemble a structure quite similar to biaryl mannosides, which have been

Palladium-catalyzed C–N and C–O bond formation of N-substituted 4-bromo-7-azaindoles with amides, amines, amino acid esters and phenols

• Rajendra Surasani,
• Dipak Kalita,
• A. V. Dhanunjaya Rao and
• K. B. Chandrasekhar

Beilstein J. Org. Chem. 2012, 8, 2004–2018, doi:10.3762/bjoc.8.227

• arylation of the heterocyclic N–H nitrogen [49][50]. To find a suitable condition for amide coupling with 7-azaindole derivatives, various biaryl/alkyl phosphine ligands, palladium catalysts, bases and reaction times, etc., were screened by using electron-deficient N-protected 4-bromo-7-azaindoles 1 as

Palladium-catalyzed dual C–H or N–H functionalization of unfunctionalized indole derivatives with alkenes and arenes

• Gianluigi Broggini,
• Egle M. Beccalli,
• Andrea Fasana and
• Silvia Gazzola

Beilstein J. Org. Chem. 2012, 8, 1730–1746, doi:10.3762/bjoc.8.198

• providing conditions to access asymmetric biaryl compounds by dual C–H functionalization [55]. In 2007, Fagnou and co-workers combined, in a single catalytic cycle, the reactivity of electron-deficient palladium(II) complexes with electron-rich arenes (through an electrophilic C–H activation mechanism) and

Extending the utility of [Pd(NHC)(cinnamyl)Cl] precatalysts: Direct arylation of heterocycles

• Anthony R. Martin,
• Anthony Chartoire,
• Alexandra M. Z. Slawin and
• Steven P. Nolan

Beilstein J. Org. Chem. 2012, 8, 1637–1643, doi:10.3762/bjoc.8.187

• -bromobenzaldehyde was also successfully involved in the direct arylation of 6. Despite its electron-withdrawing nature as well as its high reactivity, the expected biaryl was obtained in moderate yield (Table 4, entry 7). The limits of the scope were determined by switching from benzothiophene (6) to the more

Organocatalytic C–H activation reactions

• Subhas Chandra Pan

Beilstein J. Org. Chem. 2012, 8, 1374–1384, doi:10.3762/bjoc.8.159

• enantioselectivity for their reaction [25]. Organocatalytic sp2 C–H bond activation reactions The catalytic cross-coupling of arenes and aryl halides to construct biaryl compounds is an important area in synthetic organic chemistry. Transition-metal-catalyzed biaryl synthesis from unactivated arenes by C–H

• activation is well-known in the literature [26][27][28][29][30]. Stoichiometric amounts of a radical source, such as tributyltin hydride and tris(trimethylsilyl)silicon hydride [31], or irradiation [32] were also utilized for biaryl synthesis from unactivated arenes. However, organocatalysts have not been

• studied for this class of transformation. In 2010, three research groups independently reported organocatalytic biaryl synthesis from unactivated arenes and aryl halides [33][34][35]. Since these reactions follow a homolytic radical aromatic substitution mechanism (HAS) as pointed out by Studer and Curran

Synthesis and characterization of Sant-75 derivatives as Hedgehog-pathway inhibitors

• Chao Che,
• Song Li,
• Bo Yang,
• Shengchang Xin,
• Zhixiong Yu,
• Taofeng Shao,
• Chuanye Tao,
• Shuo Lin and
• Zhen Yang

Beilstein J. Org. Chem. 2012, 8, 841–849, doi:10.3762/bjoc.8.94

•  1. Accordingly, Suzuki coupling of 4-bromopyridine and 3-formylphenylboronic acid afforded biaryl aldehyde 2, which was then subjected to a reductive amination by condensation of aldehyde 2 with N-Boc-cyclohexane-1,4-diamine, followed by reduction with NaBH(OAc)3 to afford secondary amine 3

• reaction conditions, we found that the reaction proceeded well in 1,4-dioxane at 100 °C for 8 h with Na2CO3 as base in the presence of Pd(OAc)2 as catalyst, and PPh3 as ligand, providing the products in 73–85% yield. Different from the synthetic strategy of 11a–d, the pyrimidine nucleus in biaryl aldehydes

• conditions: (a) BOP, DIEA, DMF; (b) CH2Cl2, TFA. Synthesis of key intermediate biaryl aldehydes. Reagents and conditions: (a) Pd(OAc)2, PPh3, 1,4-dioxane, Na2CO3, 100 °C; (b) cat. NaOMe, MeOH; then NH4Cl; (c) acetylacetaldehyde dimethyl acetal, 1,4-dioxane, reflux; (d) SeO2, 1,4-dioxane, reflux; (e) DMF-DMA

Double N-arylation reaction of polyhalogenated 4,4’-bipyridines. Expedious synthesis of functionalized 2,7-diazacarbazoles

• Mohamed Abboud,
• Emmanuel Aubert and
• Victor Mamane

Beilstein J. Org. Chem. 2012, 8, 253–258, doi:10.3762/bjoc.8.26

• -pentylaniline (6a) was investigated with several ligands in toluene at 120 °C, and in the presence of Pd2(dba)3 as the source of metal catalyst (Scheme 2). Ligands such as Xantphos [33], biaryl monophosphines [34] and t-Bu3P [35] were tested since they were found to be very effective in the selective C-5

Carbamate-directed benzylic lithiation for the diastereo- and enantioselective synthesis of diaryl ether atropisomers

• Abigail Page and
• Jonathan Clayden

Beilstein J. Org. Chem. 2011, 7, 1327–1333, doi:10.3762/bjoc.7.156

• for the synthesis of “nonstandard” atropisomer structures containing rigid fragments joined by a hindered single bond, but which are different from the typically well-studied biaryl compounds [4][5]. These non-biaryl atropisomers have included aromatic amides [6][7][8], ureas [9], ethers [10][11][12

Synthesis of diverse dihydropyrimidine-related scaffolds by fluorous benzaldehyde-based Biginelli reaction and post-condensation modifications

• Bruno Piqani and
• Wei Zhang

Beilstein J. Org. Chem. 2011, 7, 1294–1298, doi:10.3762/bjoc.7.150

• are used as common intermediates for post-condensation modifications such as cycloaddition, Liebeskind–Srogl reaction and Suzuki coupling to form biaryl-substituted dihydropyrimidinone, dihydropyrimidine, and thiazolopyrimidine compounds. The high efficiency of the diversity-oriented synthesis is

• diversity-oriented synthesis of biaryl-substituted dihydropyrimidinone 5, thiazolopyrimidine 6, and dihydropyrimidine 7 compounds (Scheme 1). The perfluorooctanesulfonyl-attached benzaldehydes 1 were used as a key component for the Biginelli reactions [6]. The Biginelli products 4 were used as a common

• extractions (F-SPE) for purification [7]. The perfluorooctanesulfonyl group served as a phase tag for F-SPE and also as a convertible linker for the Suzuki coupling to introduce biaryl functionality to the heterocyclic skeletons [8][9][10][11][12]. Result and Discussion Fluorous benzaldehydes 1 were prepared

Bromine–lithium exchange: An efficient tool in the modular construction of biaryl ligands

• Laurence Bonnafoux,
• Frédéric R. Leroux and
• Françoise Colobert

Beilstein J. Org. Chem. 2011, 7, 1278–1287, doi:10.3762/bjoc.7.148

• analogues. So far, such a process, based on the effective discrimination between bromine atoms as a function of their chemical environment, has been observed only sporadically. Keywords: biaryl; bromine–lithium exchange; ligand; lithiation; phosphine; Introduction Atropisomeric biaryls are important

• compounds in various fields. In particular, pharmaceuticals and agrochemicals with biaryl substructures are of general interest [1]. In addition, they have widespread applications as ligands in catalysis, or in materials sciences [2]. The atropisomeric C2-symmetric binaphthyl- or biphenyl-bridged

• " substituent at a remote meta position and a bromine atom on an "unstabilized" phenyl ring. Biaryl mono- and diphosphines In the following section we will show how a large family of biaryl mono- and diphosphines becomes readily accessible through these common building-blocks. The general access is depicted in

Directed aromatic functionalization

• Victor Snieckus

Beilstein J. Org. Chem. 2011, 7, 1215–1218, doi:10.3762/bjoc.7.141

• species, derived from metal–halogen exchange, for transition metal-catalyzed cross-coupling reactions towards biaryl synthesis is furnished by Frederic Leroux; the next generation of heteroaromatic functionalization through C–H activation may be gleaned from the review of the Rouen group presented by

Recent developments in gold-catalyzed cycloaddition reactions

• Fernando López and
• José L. Mascareñas

Beilstein J. Org. Chem. 2011, 7, 1075–1094, doi:10.3762/bjoc.7.124

• )oxiranyl ketones 13 [50]. The method provides heterobicyclic products of type 14 in a highly diastereoselective fashion. In these reactions, the gold complex Au3, derived from the bulky biaryl phosphine ligand RuPhos, provided the best reaction yields (Scheme 8). From a mechanistic point of view, the

• variety of bicyclo[5.3.0]decane systems in good yields. Other gold(I) complexes, such as that including a highly donating biaryl di-tert-butylphosphine ligand Au1, also allow these cycloadditions, as recently reported by Gung and by Toste [99][100][101]. In particular, an interesting transannular

Homocoupling of aryl halides in flow: Space integration of lithiation and FeCl₃ promoted homocoupling

• Aiichiro Nagaki,
• Yuki Uesugi,
• Yutaka Tomida and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2011, 7, 1064–1069, doi:10.3762/bjoc.7.122

• salts; microreactor; organolithiums; Introduction Biaryl structures often occur in various organic compounds including natural products, bioactive compounds, functional polymers, ligands in catalysts and theoretically interesting molecules, and the oxidative homocoupling of arylmetals is one of the

• most useful methods for the construction of biaryl frameworks [1]. Stoichiometric amounts of transition metal salts such as TiCl4 [2], TlCl [3], VO(OEt)Cl2 [4], CoCl2 [5], CuCl2 [6] and Pd(OAc)2 [7] have been used for homocoupling of arylmetals. In some cases catalytic processes in the presence of a