Ligand-dependent stereoselective Suzuki–Miyaura cross-coupling reactions of β-enamido triflates

• Tomáš Chvojka,
• Athanasios Markos,
• Svatava Voltrová,
• Radek Pohl and
• Petr Beier

Beilstein J. Org. Chem. 2021, 17, 2657–2662, doi:10.3762/bjoc.17.179

• study. Substituted phenylboronic acids and vinyl triflates led to the formation of enamides 2 with high stereoselectivity and in good to high NMR yields (Scheme 2). However, isolated yields were found to be lower due to the decomposition of the formed enamides 2 during column chromatography on silica

Recent advances in palladium-catalysed asymmetric 1,4–additions of arylboronic acids to conjugated enones and chromones

• Jan Bartáček,
• Jan Svoboda,
• Martin Kocúrik,
• Jaroslav Pochobradský,
• Alexander Čegan,
• Miloš Sedlák and
• Jiří Váňa

Beilstein J. Org. Chem. 2021, 17, 1048–1085, doi:10.3762/bjoc.17.84

• phenylboronic acid to 2-cyclohexenone catalysed by L4/Pd2(dba)3·CHCl3 [41]. Plausible catalytic cycle of the addition of phenylboronic acid to 2-cyclohexenone catalysed by palladacycle PdL6 [43]. Proposed catalytic cycle for the addition of phenylboronic acids to 2-cyclohexenone catalysed by Pd-NHC complex

Chan–Evans–Lam N1-(het)arylation and N1-alkеnylation of 4-fluoroalkylpyrimidin-2(1H)-ones

• Viktor M. Tkachuk,
• Oleh O. Lukianov,
• Mykhailo V. Vovk,
• Isabelle Gillaizeau and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2020, 16, 2304–2313, doi:10.3762/bjoc.16.191

• otherwise difficult to access and hitherto unknown N1-aryl-substituted 4-trifluoromethylpyrimidin-2(1H)-ones 3b–w (Scheme 1). The product yields were found to depend on the electronic nature of the substituents on the phenyl ring. A number of commercially available phenylboronic acids with electron-donating

Aryl-substituted acridanes as hosts for TADF-based OLEDs

• Naveen Masimukku,
• Dalius Gudeika,
• Oleksandr Bezvikonnyi,
• Ihor Syvorotka,
• Rasa Keruckiene,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 989–1000, doi:10.3762/bjoc.16.88

• according to the reported procedure [28]. The subsequent alkylation of 1 using bromoethane afforded the N-ethylated dibromo compound 2 in 80% yield. The target compounds 3–6 were then obtained by Suzuki cross-coupling reactions between brominated acridan 2 and the respective phenylboronic acids in the

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine

• Piotr Pomarański,
• Piotr Roszkowski,
• Jan K. Maurin,
• Armand Budzianowski and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2018, 14, 2384–2393, doi:10.3762/bjoc.14.214

• atropselective Suzuki–Miyaura cross-coupling reaction on 3,4,5-tribromo-2,6-dimethylpyridine was studied. Results: Reactions with various amounts of ortho-substituted phenylboronic acids with 3,4,5-tribromo-2,6-dimethylpyridine gave a series of mono- di- and triarylpyridine derivatives which allowed to draw

• compounds. The opposite selectivity using differently ortho-substituted phenylboronic acids was observed. Both electron-poor and electron-rich arylboronic acids were successfully employed. These results may be helpful in the construction of chiral atropisomeric derivatives of arylpyridine. Structures of

Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry

• Katharina Hiebler,
• Georg J. Lichtenegger,
• Manuel C. Maier,
• Eun Sung Park,
• Renie Gonzales-Groom,
• Bernard P. Binks and
• Heidrun Gruber-Woelfler

Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52

• with phenylboronic acids yielding the corresponding biphenyls as product [7]. The biphenyl unit is a common structural motif in various pharmaceutically active agents and plays a crucial role in the binding affinity and the oral bioavailability of diverse APIs [8], including antihypertensive [9] and

A novel approach to oxoisoaporphine alkaloids via regioselective metalation of alkoxy isoquinolines

• Benedikt C. Melzer and
• Franz Bracher

Beilstein J. Org. Chem. 2017, 13, 1564–1571, doi:10.3762/bjoc.13.156

• , which were expected to be versatile substrates for Suzuki cross-coupling reactions with appropriate phenylboronic acids to gain methyl 2-(isoquinolin-1-yl)benzoates as the central intermediates (Scheme 1). Results and Discussion As we reported previously, metalation of 6,7-dimethoxyisoquinoline (7a) and

Catalytic Chan–Lam coupling using a ‘tube-in-tube’ reactor to deliver molecular oxygen as an oxidant

• Carl J. Mallia,
• Paul M. Burton,
• Alexander M. R. Smith,
• Gary C. Walter and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2016, 12, 1598–1607, doi:10.3762/bjoc.12.156

• ester an isolated yield of 60% was realised, but this substrate also underwent partial epimerisation (27, 71% ee determined by chiral HPLC, Scheme 2). Using N-heterocyclic substrates as the nucleophilic partner with a range of different phenylboronic acids generally gave good isolated yields (19, 20, 28

• -phenyl-1H-pyrazole (18) as the nucleophile with a number of different phenylboronic acids gave moderate to good yields (38–82% yields). In general electron-rich phenylboronic acids (19, 29–32, Scheme 2) gave better yields than electron poor ones (33–35, Scheme 2). This is probably due to the more

• ) phenylboronic acids. On the other hand changing the group at the 3-position of the phenylboronic acid gave good yields for electron-rich (30 and 32, 77% and 82% yields, respectively) but only a moderate yield of 40% for electron-poor (34) phenylboronic acids. Lower yields were also encountered for both electron

A convenient route to symmetrically and unsymmetrically substituted 3,5-diaryl-2,4,6-trimethylpyridines via Suzuki–Miyaura cross-coupling reaction

• Dariusz Błachut,
• Joanna Szawkało and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2016, 12, 835–845, doi:10.3762/bjoc.12.82

• crude products revealed in most cases the presence of three major products: symmetrical triaryls P6 (4–29) along with the desired pyridines P7 (46–66) with two different aryl rings. The results were collected in Table 2. Trial reactions with mixtures of phenylboronic acids 32 with para-substituted

• of phenyl/2-(trifluoromethyl)phenyl- and 2-methylphenyl/2-(trifluoromethyl)phenylboronic acids were applied in the presence of PdCl2(dppf) × CH2Cl2 (Table 2, entries 16 and 26), respectively. In the case of both sterically demanding reagents, the catalytic system based on S-Phos worked more

Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF₅-substituted phenylboronic esters and iodobenzenes

• George Iakobson,
• Junyi Du,
• Alexandra M. Z. Slawin and
• Petr Beier

Beilstein J. Org. Chem. 2015, 11, 1494–1502, doi:10.3762/bjoc.11.162

• [72]. Straightforward access to SF5-phenylboronic acids or boronates would be highly desirable since it would allow easy installation of the SF5-phenyl group by the subsequent Suzuki–Miyaura reaction. Nitro-(pentafluorosulfanyl)benzenes are the primary industrial SF5-aromatics, therefore the easiest

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

• 58030, tel.: +52 443 326 5790; fax: +52 443 326 5788 10.3762/bjoc.10.299 Abstract A simple and efficient catalytic system based on a Pd complex of 4-aminoantipyrine, 4-AAP–Pd(II), was found to be highly active for Suzuki–Miyaura cross-coupling of aryl iodides and bromides with phenylboronic acids under

• , we report the synthesis of the new 4-aminoantipyrine–Pd(II) complex [4-AAP–Pd(II)] by mixing Li2PdCl4, 4-aminoantipyrine in presence of NaOAc in MeOH at room temperature, and its performance as catalysts in SM cross-coupling reaction of structurally different aryl halides with phenylboronic acids

• scope of the SM cross-coupling reaction using the 4-AAP–Pd(II) complex, we examined the reactions of a wide array of electronically diverse aryl iodides and bromides with electron-withdrawing or electron-donating substituents on the phenylboronic acids. The effects of the substituents of the arylboronic

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

• -phenylboronic acid to synthesize the corresponding substituted binaphthyl or phenyl-naphthyl skeleton substrates with axial chirality. To maintain the axial chirality within the substrates, a steric hindrance effect at the ortho position of phenylboronic acids was required, rendering the non-ortho substituted

Palladium(II)-catalyzed Heck reaction of aryl halides and arylboronic acids with olefins under mild conditions

• Tanveer Mahamadali Shaikh and
• Fung-E Hong

Beilstein J. Org. Chem. 2013, 9, 1578–1588, doi:10.3762/bjoc.9.180

• reaction conditions.a Substrate scope in the Heck arylation reaction of phenylboronic acids with olefins.a Substrate scope in Heck arylation reaction of phenylboronic acids with olefins.a Supporting Information Supporting Information File 292: General procedure for Heck reactions, preparation of complex 6

Coupling of C-nitro-NH-azoles with arylboronic acids. A route to N-aryl-C-nitroazoles

• Marta K. Kurpet,
• Aleksandra Dąbrowska,
• Małgorzata M. Jarosz,
• Katarzyna Kajewska-Kania,
• Nikodem Kuźnik and
• Jerzy W. Suwiński

Beilstein J. Org. Chem. 2013, 9, 1517–1525, doi:10.3762/bjoc.9.173

• phenylboronic acids gave in most cases lower yields in comparison to para-substituted ones (Table 5, entries 2,3,5–8,11–14). This might be a result of steric hindrance around the reaction center in the catalytic cycle. Applicability of the synthetic procedure to the preparation of various N-aryl-C-nitroazoles

Conformational analysis and intramolecular interactions in monosubstituted phenylboranes and phenylboronic acids

• Josué M. Silla,
• Rodrigo A. Cormanich,
• Roberto Rittner and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2013, 9, 1127–1134, doi:10.3762/bjoc.9.125

• ; monosubstituted phenylboranes; phenylboronic acids; Introduction Boronic acid derivatives have been widely studied because of their good performance as pharmaceutical agents, serving in the development of enzyme inhibitors of peptidases/proteases, proteasomes, arginase, nitric oxide synthase (NOS), and

• hydrogen bonding, 2-X-phenylboranes (X = F, Cl, Br, NH2, PH2, OH and SH) were also evaluated theoretically (Figure 1), in order to account for the importance of nX→pB interactions free from interference of the OH∙∙∙X hydrogen bond present in the 2-substituted phenylboronic acids. In order to achieve these

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Branching out at C-2 of septanosides. Synthesis of 2-deoxy-2-C-alkyl/aryl septanosides from a bromo-oxepine

• Supriya Dey and
• Narayanaswamy Jayaraman

Beilstein J. Org. Chem. 2012, 8, 522–527, doi:10.3762/bjoc.8.59

• bromo-oxepine 2, efforts were undertaken to implement C–C bond forming Suzuki and Sonogashira coupling reactions. Suzuki reactions were undertaken by involving phenylboronic acid and substituted phenylboronic acids [26][27], in the presence of Pd(OAc)2 (10 mol %) and Cs2CO3 in 1,4-dioxane at 98 °C

Studies on Pd/NiFe₂O₄ catalyzed ligand-free Suzuki reaction in aqueous phase: synthesis of biaryls, terphenyls and polyaryls

• Sanjay R. Borhade and
• Suresh B. Waghmode

Beilstein J. Org. Chem. 2011, 7, 310–319, doi:10.3762/bjoc.7.41

• synthesis of terphenyls as well as polyaryls using di- and tribromoarenes with phenylboronic acids in o-xylene as solvent at 120 °C for 20 h under a N2 atmosphere [61]. We have studied the usefulness of Pd/NiFe2O4 catalyst for the synthesis of terphenyls and polyaryls in a single step under the optimized

• reaction conditions. The results thus obtained are summarized in Table 5. The reactions were performed by using 1.0 mol % of Pd at 90 °C and 3.5 equiv of arylboronic acid in 1:1 DMF/H2O solvent for 2 h. The reaction between various di- and trihalo aryls with phenyl- and 3-(hydroxymethyl)phenylboronic acids