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

• added as a co-catalyst [171]. Imamoto et al. have developed a method for the palladium-catalyzed C–P bond formation using secondary phosphine boranes [41]. The authors also discovered how the choice of the solvent influences the stereochemistry of 100. When the coupling between aryl iodide 99 and

Practical synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides via conventional and decarboxylative copper-free Sonogashira coupling reactions

• Andrea Caporale,
• Stefano Tartaggia,
• Andrea Castellin and
• Ottorino De Lucchi

Beilstein J. Org. Chem. 2014, 10, 384–393, doi:10.3762/bjoc.10.36

• acid has been reported by Lee, in which the Pd-catalyzed coupling of propiolic acid with an aryl iodide is followed by the addition of the Cu-catalyst, which promotes the protodecarboxylation of the arylpropiolic acid intermediate to the desired alkyne in good yields [70]. Acetylenic compounds and

Synthesis of 3,4-dihydro-1,8-naphthyridin-2(1H)-ones via microwave-activated inverse electron-demand Diels–Alder reactions

• Salah Fadel,
• Youssef Hajbi,
• Mostafa Khouili,
• Said Lazar,
• Franck Suzenet and
• Gérald Guillaumet

Beilstein J. Org. Chem. 2014, 10, 282–286, doi:10.3762/bjoc.10.24

• subjected to a Sonogashira cross-coupling reaction. Thus, treating compounds 6–9 in DME with Pd(PPh3)2Cl2 (5 mol %), CuI, Et3N and aryl iodide, gave the cross-coupling products 14–21 in very good yields (Scheme 5). The results are summarized in Table 4. Intramolecular inverse electron-demand Diels–Alder

Microwave-assisted synthesis of 5,6-dihydroindolo[1,2-a]quinoxaline derivatives through copper-catalyzed intramolecular N-arylation

• Fei Zhao,
• Lei Zhang,
• Hailong Liu,
• Shengbin Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2013, 9, 2463–2469, doi:10.3762/bjoc.9.285

• reagent A (2a) was synthesized in a total yield of 67% (Table 2, entry 8), while it took four steps to afford this molecule with only 24% total yield in the original literature [12]. Next, the approach was investigated with respect to the structural variation of the aryl iodide moiety. The reaction

Oxidative 3,3,3-trifluoropropylation of arylaldehydes

• Akari Ikeda,
• Masaaki Omote,
• Shiho Nomura,
• Miyuu Tanaka,
• Atsushi Tarui,
• Kazuyuki Sato and
• Akira Ando

Beilstein J. Org. Chem. 2013, 9, 2417–2421, doi:10.3762/bjoc.9.279

• . Approximately at the same time, our research group demonstrated that (E)-trimethyl(3,3,3-trifluoroprop-1-en-1-yl)silane (1) effectively participated in a Hiyama cross-coupling reaction with aryl iodide to construct β-trifluoromethylstyrenes in good to excellent yield [31][32]. In the course of this study, we

Cu-catalyzed trifluoromethylation of aryl iodides with trifluoromethylzinc reagent prepared in situ from trifluoromethyl iodide

• Yuzo Nakamura,
• Motohiro Fujiu,
• Tatsuya Murase,
• Yoshimitsu Itoh,
• Hiroki Serizawa,
• Kohsuke Aikawa and
• Koichi Mikami

Beilstein J. Org. Chem. 2013, 9, 2404–2409, doi:10.3762/bjoc.9.277

• challenge. Recently, Daugulis and co-workers reported the trifluoromethylation of aryl iodide catalyzed by copper(I) chloride with Zn(CF3)2 prepared in situ from TMP2Zn and fluoroform (CHF3), but only one substrate was investigated to provide the trifluoromethylated product only in a moderate yield [17]. As

• ®), Bicalutamide (Casodex®), Aprepitant (Emend®), and Nilutamide (Nilandron®). Results and Discussion The preparation of the trifluoromethylzinc reagent Zn(CF3)I was initially examined in the context of the in situ Cu-catalyzed trifluoromethylation of aryl iodide 1 under various conditions. The results of the

• ][20][21] followed by aryl iodide 1a. In this catalytic system, solvents showed significant effects on the preparation and catalytic reactivity of Zn(CF3)I. No reaction was observed in less polar solvents such as toluene (Table 1, entry 1). Even in THF, CH3CN, DMSO, and NMP, the desired product 2a was

An easy direct arylation of 5-pyrazolones

• Hao Gong,
• Yiwen Yang,
• Zechao Wang and
• Chunxiang Kuang

Beilstein J. Org. Chem. 2013, 9, 2033–2039, doi:10.3762/bjoc.9.240

• relatively low yields (Table 2, entries 3, 6–8). Entries 1 and 2 show that the yield of products was lower when using aryl bromide than when using aryl iodide, and 2-bromopyridine also provided 3i in moderate yield (Table 2, entry 10). Next, we investigated the scope of 5-pyrazolone 1 substrates. Table 3

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

• subjected to cross-coupling to produce the corresponding 1,2-disubstituted olefins. The results are summarized in Table 2. Both aryl bromide and aryl iodide performed well (Table 2, entries 1 and 2) under these conditions. However, the aryl chloride was found to be less reactive giving the corresponding

Practical synthesis of indoles and benzofurans in water using a heterogeneous bimetallic catalyst

• Cybille Rossy,
• Eric Fouquet and
• François-Xavier Felpin

Beilstein J. Org. Chem. 2013, 9, 1426–1431, doi:10.3762/bjoc.9.160

• 0.45 µm, 47 mm), washed with MeOH and dried under vacuum. ICP analyses were performed on the filtrate to verify the final Pd-metal loading on carbon to be 5 wt % and Cu-metal loading on carbon to be 3.6 wt %. General procedure for the preparation heterocycles: In a sealed tube, aryl iodide (0.5 mmol

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

• States of America 10.3762/bjoc.9.102 Abstract We report a new synthesis of phenanthridines based on palladium-catalyzed picolinamide-directed sequential C–H functionalization reactions starting from readily available benzylamine and aryl iodide precursors. Under the catalysis of Pd(OAc)2, the ortho-C–H

• 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

• sequential palladium-catalyzed picolinamide (PA)-directed C–H functionalization reactions beginning from easily accessible PA-protected benzylamine and aryl iodide precursors. Results and Discussion New synthetic strategy for phenanthridine compounds. The picolinamide (PA) group has been shown to be an

Efficient Cu-catalyzed base-free C–S coupling under conventional and microwave heating. A simple access to S-heterocycles and sulfides

• Silvia M. Soria-Castro and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2013, 9, 467–475, doi:10.3762/bjoc.9.50

• -catalyzed reaction with a different aryl iodide to yield asymmetric diaryl sulfides. With this strategy we synthesized different sulfur compounds. Accordingly, a solution of benzene thiolate obtained from this methodology affords bis(phenyl)disulfide (51%) after oxidation by KI/I2, by subsequent

• addition of CuI/1,10-phenanthroline (10 and 20 mol %, respectively) was required, together with the new aryl iodide (1 equiv). After stirring for 24 h at 100 °C, the work-up of the reaction was similar to that of Method A. Examples of some pharmaceutically and chemically important derivatives. Synthesis of

Copper-catalyzed CuAAC/intramolecular C–H arylation sequence: Synthesis of annulated 1,2,3-triazoles

• Rajkumar Jeyachandran,
• Harish Kumar Potukuchi and
• Lutz Ackermann

Beilstein J. Org. Chem. 2012, 8, 1771–1777, doi:10.3762/bjoc.8.202

• 3a (Table 1). Notably, the envisioned C–H bond functionalization occurred readily with the aryl iodide 3a when catalytic amounts of CuI were used, even at a reaction temperature as low as 60 °C, with optimal yields being obtained at 80 °C (Table 1, entries 1–6). While the transformation proceeded

Hybrid super electron donors – preparation and reactivity

• Jean Garnier,
• Douglas W. Thomson,
• Shengze Zhou,
• Phillip I. Jolly,
• Leonard E. A. Berlouis and
• John A. Murphy

Beilstein J. Org. Chem. 2012, 8, 994–1002, doi:10.3762/bjoc.8.112

• sodium hydride base has a very important and selective effect on some of these electron-transfer reactions, and a rationale for this is proposed. Keywords: aryl iodide; electron transfer; hybrid donors; reduction; Introduction Alkenes that are substituted by four heteroatoms are notable for their ease

• excess NaH was filtered prior to the addition of substrate 30. Reaction of iodoarene 28 led to an inseparable mixture of 29 and 28 in a 2:1 ratio; based on the mass recovered, this corresponded to 29 (46%) and 28 (22%). By comparison, reaction with aryl iodide 30, again at room temperature, afforded a

Synthesis and antifungal properties of papulacandin derivatives

• Marjolein van der Kaaden,
• Eefjan Breukink and
• Roland J. Pieters

Beilstein J. Org. Chem. 2012, 8, 732–737, doi:10.3762/bjoc.8.82

• spiroketal unit, which is introduced in a palladium-catalyzed cross-coupling reaction of a glycal silanolate and an aryl iodide followed by an oxidative spiroketalization. Four different variants were made, differing in the nature of the acyl side chain with respect to the length, and in the number and

• primary alcohol to give 7 (Scheme 1). This compound was iodinated by using N-iodosuccinimide (NIS), and finally the free hydroxy group was protected with a pivaloyl group to give aryl iodide 12. Derivatives 13 and 14, providing alternative core structures, were prepared similarly. The glucose moiety at

• the core of the structure, as present in papulacandin D, was approached from glycal 15. The aim was to obtain a silanol such as 22 for coupling to an aryl iodide in the palladium-catalyzed cross-coupling reactions of silanolates, as pioneered and applied by the Denmark group (Scheme 2) [48]. The

Pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes via a one-pot Sonogashira–Glaser cyclization sequence

• Dominik Urselmann,
• Dragutin Antovic and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1499–1503, doi:10.3762/bjoc.7.174

• of this novel pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes was studied (Scheme 3). Starting from (hetero)aryl iodide 1 all reactions were carried out on a 2 mmol scale to give symmetrical 2,5-di(hetero)arylthiophenes 2 as stable, crystalline solids (with the exception of 2b) in

• Sonogashira–Glaser cyclization sequence (yields refer to 0.5 equiv of (hetero)aryl iodide). aOnly one equiv of TMSA was applied in the Sonogashira step. bAccording to elemental analysis compound 2f was obtained with 25% hydrate. cm-Iodo nitrobenzene (1g) was applied as a starting material. dAccording to

Amines as key building blocks in Pd-assisted multicomponent processes

• Didier Bouyssi,
• Nuno Monteiro and
• Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

• synthesis of isoindolones and phthalazones starting from ortho-halogenated cinnamates 34 and related compounds in the presence of hydrazine derivatives and carbon monoxide. The process is thought to begin with carbonylation of the starting aryl iodide to give an acylpalladium species 35, which is

• precursor 49 in situ through a Pd/Cu mediated coupling reaction between (trimethylsilyl)acetylene (TMSA) with an aryl iodide, followed by a desilylation reaction. The subsequent addition of the third partner, an o-iodoanilide derivative, allowed a Pd/Cu tandem C–C/C–N-bond-forming reaction. The main

• advantage of this multicomponent reaction is to suppress the isolation of the pure form of the arylalkyne derivatives, which often represents a problem due to their ability to dimerize. This one-pot four-step reaction proceeded well with a series of electron-rich and electron-poor aryl iodide derivatives

Functionalization of heterocyclic compounds using polyfunctional magnesium and zinc reagents

• Paul Knochel,
• Matthias A. Schade,
• Sebastian Bernhardt,
• Georg Manolikakes,
• Albrecht Metzger,
• Fabian M. Piller,
• Christoph J. Rohbogner and
• Marc Mosrin

Beilstein J. Org. Chem. 2011, 7, 1261–1277, doi:10.3762/bjoc.7.147

• ) reacts with magnesium powder in the presence of LiCl (1.5 equiv) and ZnCl2 (1.1 equiv) to provide the intermediate magnesium species 38, which is immediately trapped with ZnCl2 leading to the zinc reagent 39 in high yields. Subsequent Pd-catalyzed cross-coupling of 39 with an aryl iodide provides the

• iPrMgCl·LiCl also proves to be very practical for the generation of polyfunctional alkenylmagnesium reagents, which react only slowly with iPrMgCl [40][41], as well as for the preparation of arylmagnesium reagents bearing sensitive functionalities, such as triazene. Thus, aryl iodide 79 is treated with

A practical microreactor for electrochemistry in flow

• Kevin Watts,
• William Gattrell and
• Thomas Wirth

Beilstein J. Org. Chem. 2011, 7, 1108–1114, doi:10.3762/bjoc.7.127

• density: 2.22 mA/cm2) and collected at the outlet to give 7a with 40% yield (72 mg, 0.4 mmol). The product was identified by GC/MS m/z (EI): M+ 183.3. General procedure for the synthesis of iodonium salts 11 A solution of aryl iodide 8 (0.1 M) and aryl compound 9 (0.3 M) was prepared in 2 M H2SO4

Nano copper oxide catalyzed synthesis of symmetrical diaryl sulfides under ligand free conditions

• K. Harsha Vardhan Reddy,
• V. Prakash Reddy,
• A. Ashwan Kumar,
• G. Kranthi and
• Y.V.D. Nageswar

Beilstein J. Org. Chem. 2011, 7, 886–891, doi:10.3762/bjoc.7.101

• , functions under ligand free conditions and is recyclable for up to four cycles without loss of catalytic activity [20][39][40][41] (Table 4). Experimental General procedure for the synthesis of diaryl sulfides: A mixture of aryl iodide (2.0 mmol), potassium thiocyanate (1.5 mmol), nano CuO (5.0 mol %), and

Unusual behavior in the reactivity of 5-substituted-1H-tetrazoles in a resistively heated microreactor

• Bernhard Gutmann,
• Toma N. Glasnov,
• Tahseen Razzaq,
• Walter Goessler,
• Dominique M. Roberge and
• C. Oliver Kappe

Beilstein J. Org. Chem. 2011, 7, 503–517, doi:10.3762/bjoc.7.59

• demonstrated full conversion to cinnamic ester 14 in the initial product fractions exiting the flow reactor. To establish for how long this “palladated” steel coil could be used without additional amounts of catalyst being added, 15 mL of reaction mixture containing 1.125 g of aryl iodide 12 (8.45 mmol) were

• active species. Presumably, the heterogeneous “Pd-on-steel” pre-catalyst is initially solubilized by oxidative addition of the aryl iodide and enters the catalytic cycle in the form of a soluble Pd species. Therefore, significant levels of Pd leaching are observed for the reaction mixture, not for pure

The preparation of 3-substituted-1,5-dibromopentanes as precursors to heteracyclohexanes

• Bryan Ringstrand,
• Martin Oltmanns,
• Jeffrey A. Batt,
• Aleksandra Jankowiak,
• Richard P. Denicola and
• Piotr Kaszynski

Beilstein J. Org. Chem. 2011, 7, 386–393, doi:10.3762/bjoc.7.49

• % [17][38]. The downside to Method 1C is that an excess of Grignard reagent (3–4 equiv) is required; therefore, it is not economical with respect to the alkyl halide. Method 1D also uses glutaconate diester, which is reacted with an aryl iodide in the presence of Pd(0) under Heck conditions. The

Donor-acceptor substituted phenylethynyltriphenylenes – excited state intramolecular charge transfer, solvatochromic absorption and fluorescence emission

• Ritesh Nandy and
• Sethuraman Sankararaman

Beilstein J. Org. Chem. 2010, 6, 992–1001, doi:10.3762/bjoc.6.112

• , 127.8, 127.7, 127.5, 127.1, 123.6, 123.5, 123.4, 121.4, 93.0, 89.5 ppm; ESI Q-TOF MS m/z 433 [M + H]+; HRMS calcd for C33H21O [M + H]+ 433.1592; found, 433.1593. General procedure for the synthesis of 1f–g. A Schlenk flask was charged with the corresponding aryl iodide (0.6 mmol), Pd(PPh3)2Cl2 (0.011 g

Polar tagging in the synthesis of monodisperse oligo(p-phenyleneethynylene)s and an update on the synthesis of oligoPPEs

• Dhananjaya Sahoo,
• Susanne Thiele,
• Miriam Schulte,
• Navid Ramezanian and
• Adelheid Godt

Beilstein J. Org. Chem. 2010, 6, No. 57, doi:10.3762/bjoc.6.57

• derived by the removal of either the HOM or the TIPS group. The HOM protected 1,4-diethynylbenzene 3a1 is coupled with 1,4-diiodobenzene to obtain aryl iodide 4a2. This is coupled with the TIPS protected 1,4-diethynylbenzene 21 in the convergent step. It has been shown that HOM can be exchanged for 1

A convenient method for preparing rigid-core ionic liquid crystals

• Julien Fouchet,
• Laurent Douce,
• Benoît Heinrich,
• Richard Welter and
• Alain Louati

Beilstein J. Org. Chem. 2009, 5, No. 51, doi:10.3762/bjoc.5.51

• -methyl-1H-imidazol-3-ium mesogenic salts. Synthesis of the imidazole A. Reaction conditions: (i) aryl iodide (1.37 mmol), imidazole (1.69 mmol), K2CO3 (1.51 mmol), Cu(II)NaY (148 mg), 72 h at 180 °C in a sealed tube. Synthesis of methyl imidazolium 1a. Reaction conditions: (i) MeI in sealed tube, 54 h at

Reduction of arenediazonium salts by tetrakis(dimethylamino)ethylene (TDAE): Efficient formation of products derived from aryl radicals

• Mohan Mahesh,
• John A. Murphy,
• Franck LeStrat and
• Hans Peter Wessel

Beilstein J. Org. Chem. 2009, 5, No. 1, doi:10.3762/bjoc.5.1

• arenediazonium cation) to the phenyl anion (+0.05 V vs SCE). Thus, it had long been noted that cyclic voltammetry of aryl halides, particularly iodides, can give rise to a single two-electron wave in the reductive part of the cycle. The first electron converts the aryl iodide to the corresponding aryl radical