Synthesis of diverse indole libraries on polystyrene resin – Scope and limitations of an organometallic reaction on solid supports

• Kerstin Knepper,
• Sylvia Vanderheiden and
• Stefan Bräse

Beilstein J. Org. Chem. 2012, 8, 1191–1199, doi:10.3762/bjoc.8.132

• calculated as if complete conversion had taken place. GP 3 - Suzuki reaction: Under an argon atmosphere, one equiv of the respective 7-bromo-1H-indole-6-carboxymethyl-polystyrene is suspended in DMF (0.1 mmol/mL) together with 0.10 equiv of tetrakis(triphenylphosphine)palladium and two equiv of boronic acid

• indole 3{h,d} and methyl 3-amino-4-chlorobenzoate (aniline): Isolated yields. Diverse synthesis of indoles using Bartoli reactions. aSee [24]. Stille reaction on solid supports. Suzuki reaction on solid supports. Sonogashira–Hagihara reaction on solid supports. Cleavage of indoles from solid supports

Toward unidirectional switches: 2-(2-Hydroxyphenyl)pyridine and 2-(2-methoxyphenyl)pyridine derivatives as pH-triggered pivots

• Christina Tepper and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2012, 8, 977–985, doi:10.3762/bjoc.8.110

• 9 in which a bridge consisting of two pyridine units spans over the peptidic clamp 14 (Scheme 3). Due to the chirality of the clamp, the bridge adopts a specific conformation (in this case the P conformation). The desired pyridine switches 10 and 12 can easily be synthesized by a Suzuki reaction of

meta-Oligoazobiphenyls – synthesis via site-selective Mills reaction and photochemical properties

• Raphael Reuter and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2012, 8, 877–883, doi:10.3762/bjoc.8.99

• reacted with mCPBA in THF to yield the nitroso derivative 10 in a good yield of 69%. With all the necessary building blocks in hand, the assembly of oligomer 2 was started with a Suzuki reaction of 9 with 3-aminophenylboronic acid pinacolate (11) to prepare biphenyl 12 (Scheme 3). The reaction proceeded

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

• acceptor moieties in C–C bond forming Heck, Suzuki and Sonogashira coupling reactions, thus affording 2-deoxy-2-C-alkyl/aryl septanosides. Whereas Heck and Sonogashira coupling reactions afforded 2-deoxy-2-C-alkenyl and -alkynyl derivatives, respectively, the Suzuki reaction afforded 2-deoxy-2-C-aryl

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

• heated in a Biotage Initiator microwave synthesizer at 120 °C for 20 min. The resulting mixture was purified by F-SPE eluted with 40 mL of 80:20 MeOH/H2O and then 40 mL of acetone. The acetone fraction was concentrated to give 4c (1.3 g) in 90% yield. Typical Suzuki reaction procedure: Synthesis of 5

Air-stable, recyclable, and time-efficient diphenylphosphinite cellulose-supported palladium nanoparticles as a catalyst for Suzuki–Miyaura reactions

• Qingwei Du and
• Yiqun Li

Beilstein J. Org. Chem. 2011, 7, 378–385, doi:10.3762/bjoc.7.48

• recovered catalyst after being reused six times (b) at the same magnification. Recycling of Cell–OPPh2–Pd0 for the Suzuki reaction. Reaction conditions: 4-iodoanisole (1.0 mmol), phenylboronic acid (1.2 mmol), K2CO3 (2.0 mmol), Cell–OPPh2–Pd0 (0.015 g, 0.005 mmol of Pd), and 5.0 cm3 95% ethanol heating

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

• catalysis; nickel ferrite; polyaryls; Suzuki reaction; terphenyls; Introduction Recently, transition metal catalyzed cross-coupling protocols have generated immense interest owing to their versatile applications in organic synthesis [1][2][3][4]. The Pd catalyzed Suzuki reaction between aryl halides with

• products, pharmaceutical intermediates, pesticides, advanced materials and liquid crystals [8][9][10]. These applications, in turn, have led to the production of biaryls and polyaryls on the industrial scale [11]. The Suzuki reaction is usually performed with homogeneous palladium catalysts in the presence

• halides and the limited scope of the Suzuki reaction under ligand free conditions in the absence of additives thus faced with these limitations requires a fresh approach to carry out the Suzuki reaction. Recently, the use of Pd supported on surface-modified nano NiFe2O4 catalyst for the Heck and Suzuki

Studies on polynuclear furoquinones. Part 1: Synthesis of tri- and tetra- cyclic furoquinones simulating BCD/ABCD ring system of furoquinone diterpenoids

• Faruk H. Shaik and
• Gandhi K. Kar

Beilstein J. Org. Chem. 2009, 5, No. 47, doi:10.3762/bjoc.5.47

• extended for the synthesis of the tricyclic furoquinone, naphtho[1,2-b]furan-4,5-dione. Keywords: Fremy’s salt oxidation; furonaphthoquinone; furophenanthraquinone; Suzuki reaction; Introduction Chemistry of furoquinones [1][2][3][4][5][6][7][8], especially the tetra cyclic furoquinones isolated from

• of aryl-furyl C–C bond via Suzuki reaction [35] and the generation of the quinone functionality by oxidation of a phenolic intermediate (Figure 2). Retrosynthesis of the molecule showed that the required phenolic compound can easily be achieved in 7–8 steps starting from 2-bromo-3,4-dihydro-1

• converted (KCN/DMF) to the nitrile derivative 5 which on hydrolysis (KOH/EtOH-H2O, reflux) followed by esterification with CH2N2 furnished methyl 2-(2-bromo-1-naphthyl)acetate 7 in overall good yield. The bromo ester was then subjected to Suzuki reaction with furan-2-boronic acid. Reaction of compound 7

Regioselective alkynylation followed by Suzuki coupling of 2,4-dichloroquinoline: Synthesis of 2-alkynyl- 4-arylquinolines

• Ellanki A. Reddy,
• Aminul Islam,
• K. Mukkanti,
• Venkanna Bandameedi,
• Dipal R. Bhowmik and
• Manojit Pal

Beilstein J. Org. Chem. 2009, 5, No. 32, doi:10.3762/bjoc.5.32

• summarized in Table 2. The Suzuki reaction was carried out using arylboronic acids in the presence of (PPh3)2PdCl2 as a catalyst, CsCO3 as a base, tricyclohexyl phophine, (PCy3) as a ligand in dioxane–water at 80 °C. The arylboronic acids used in this reaction include phenylboronic acid (entries 1–6, Table 2

• of 2,4-dichloroquinoline at C-2 position. The 2-alkynyl-4-chloroquinolines 3 thus formed then undergo Suzuki reaction in the next step. Oxidative addition of Pd0 generated in situ to compound 3 followed by trans-organometallation of the resultant aryl-palladium complex formed with arylboronic acids

Polyionic polymers – heterogeneous media for metal nanoparticles as catalyst in Suzuki–Miyaura and Heck–Mizoroki reactions under flow conditions

• Klaas Mennecke and
• Andreas Kirschning

Beilstein J. Org. Chem. 2009, 5, No. 21, doi:10.3762/bjoc.5.21

• excellent. Aryl chlorides did not react with catalyst 3 under flow conditions. To fully explore the potential of polyionic gel 3 its reusability was investigated next. The Suzuki reaction of 4-bromotoluene (6) with phenylboronic acid (10) served as model reaction. After each reaction the continuous flow

• removing traces of soluble Pd species. Top: Reactor (1–2 mL dead volume) with functionalized Raschig-rings; bottom: TEM-micrographs of Pd(0) nanoparticles on optimized polyionic gel (left and central) and Raschig-rings (right). Repeated Suzuki reaction of 4-bromotoluene (6) with phenylboronic acid (10