Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas

• Zhenghui Liu,
• Peng Wang,
• Zhenzhong Yan,
• Suqing Chen,
• Dongkun Yu,
• Xinhui Zhao and
• Tiancheng Mu

Beilstein J. Org. Chem. 2020, 16, 645–656, doi:10.3762/bjoc.16.61

• lower yields (21 61% and 22 60%). Also, iodobenzenes with an acetyl group in either ortho, meta, or para-position gave the products in satisfactory yields (23 79%, 24 81% and 25 87%). 1-Iodo-3,4-methylenedioxybenzene performed well providing aldehyde 26 with 92% yield. Aryl iodide with an acetamido

• corresponding aldehydes 36–42 were isolated with yields of 65−73%. Isotope labeling experiments Isotope labeling experiments were conducted to study the mechanism of the reductive carbonylation of aryl iodide with CO and H2 under our optimized conditions, using 13CO and D2 instead of CO and H2, respectively, as

• ]. First, RhCl3·3H2O reacted with PPh3 to form Rh(PPh3)3Cl (A), followed by an oxidative addition of Rh(PPh3)3Cl (A) to the aryl iodide, producing the corresponding arylrhodium complex (B). Then, the coordination and insertion of CO led to the formation of benzoylrhodium complex (C). Next, metathesis with

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• corresponding aryl iodide. The aryl radical can then add to the allylating reagent, which, after tosyl radical elimination, provides the desired product. Finally, the active catalyst is regenerated thanks to the use of DIPEA as a sacrificial reductant. Note that this reaction was inefficient with aryl iodides

• , based on their findings, suggested the following mechanism: After irradiation under blue light, the excited [Cu(I)]* complex is reduced by the organic base DIPEA to produce a [Cu(0)] complex. The latter undergoes an SET with the aryl iodide to generate the radical anion from aryl iodide, which collapses

• moderate to good yields, and the functional group tolerance was excellent. Later in 2018, Evano and co-workers used their methodology to reduce aryl iodide for the synthesis of the alkaloids rosettacin, luotonin A, and deoxyvasicinone (Scheme 22) [37]. The developed strategy relied on the addition of an

Room-temperature Pd/Ag direct arylation enabled by a radical pathway

• Amy L. Mayhugh and
• Christine K. Luscombe

Beilstein J. Org. Chem. 2020, 16, 384–390, doi:10.3762/bjoc.16.36

• cycle. This type of mechanism has been previously proposed for aryl and alkene alkylations [27][28], but not for direct arylation systems. A possible mechanism is outlined in Scheme 3, informed by the previous reports [27][28][29][30]. The aryl iodide 4 undergoes SET with an excited palladium(0) species

Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids

• László Orha,
• József M. Tukacs,
• László Kollár and
• László T. Mika

Beilstein J. Org. Chem. 2019, 15, 2907–2913, doi:10.3762/bjoc.15.284

• catalytic system could be applied to various iodoarene substrates and the substrate reactivity was not influenced dramatically by the electronic parameters of the substituents. Both electron-withdrawing (chloro, fluoro and bromo) and electron-donating (methyl, methoxy) groups were tolerated on the aryl

• iodide (Table 3, entries 2–7). Under identical conditions, 2-iodothiophene, and iodopyridine derivatives could also easily be converted to the corresponding acetylene with good or even excellent isolated yields (3i–n). When 2-amino-3-iodopyridine (1i) was converted no C–N bond formation was detected

Thermal stability of N-heterocycle-stabilized iodanes – a systematic investigation

• Andreas Boelke,
• Yulia A. Vlasenko,
• Mekhman S. Yusubov,
• Boris J. Nachtsheim and
• Pavel S. Postnikov

Beilstein J. Org. Chem. 2019, 15, 2311–2318, doi:10.3762/bjoc.15.223

• cyclic (33) diaryliodonium salt. Pseudocyclic salt 25 was heated to 185 °C and the resulting oily residue was analyzed by GC–MS (Scheme 1a). Besides dearylation to aryl iodide 25a we observed the formation of an N-arylated product 25b in significant amounts. In a similar experiment compound 33 was heated

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

Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

• Edorta Martínez de Marigorta,
• Jesús M. de Los Santos,
• Ana M. Ochoa de Retana,
• Javier Vicario and
• Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

• the authors to propose that the first stage of the reaction would be the insertion of carbon monoxide into the Ar–I bond to produce aryl iodide 107, followed by the reaction with the nitrogen nucleophile to form amide intermediate 108. Finally, intramolecular Michael addition would furnish lactam unit

• by a radical process promoted by UV irradiation, with an initial formation of aryl radical 116 from the corresponding aryl iodide 113 (Scheme 33). This radical would cyclize in an intramolecular 5-exo mode to furnish cyclic radical 117 which, in turn, can be caught by intermediate 118, formed by

• -diarylallylidene)oxindoles 132, respectively. Initially [114][115], using arylboronic acids 130 (R = Ar2), a variety of twenty-one diarylmethylene oxindoles 131 were obtained with good yields. When aryl iodide and arylboronic acids bearing different substituents are used, the expected stereochemistry of the

A novel and efficient synthesis of phenanthrene derivatives via palladium/norbornadiene-catalyzed domino one-pot reaction

• Yue Zhong,
• Wen-Yu Wu,
• Shao-Peng Yu,
• Tian-Yuan Fan,
• Hai-Tao Yu,
• Nian-Guang Li,
• Zhi-Hao Shi,
• Yu-Ping Tang and
• Jin-Ao Duan

Beilstein J. Org. Chem. 2019, 15, 291–298, doi:10.3762/bjoc.15.26

• conditions in hand (Table 1, entry 3), we expanded the aryl iodide substrates of this reaction (Scheme 2). As a result, it was found that both electron-deficient and electron-rich aryl iodides progressed well in the transformation, and the yield of relevant phenanthrene derivatives y-2–y-15 was quite well

• is presented in Scheme 5. As is commonly considered, the aryl-PdII complex A is formed by oxidative addition of aryl iodide to the Pd0 complex, which is followed by the insertion of norbornadiene to the C–Pd bond of A to produce B. Then, an ortho-C–H activation reaction occurs to B, which offers

• with aryl iodide (0.30 mmol, 1.0 equiv), ortho-bromobenzoyl chlorides (0.36 mmol, 1.2 equiv), norbornadiene (0.60 mmol, 2.0 equiv), Pd(OAc)2 (5 mol %), triphenylphosphine (12.5 mol %), Cs2CO3 (0.675 mmol, 2.25 equiv), and DMF (4 mL). The mixture was stirred at 105 °C under nitrogen atmosphere for 10 h

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

• . Unsymmetrical internal alkynes bearing 4-Me2NC6H4 and 4-MeOC6H4 moieties (16f and 16g) afforded 17f-D, 17g-D, and 17g-Ar regioselectively after treatment with D2O or aryl iodide/Pd catalyst. A possible reaction mechanism for the carboxyzincation reaction is displayed in Scheme 17. First, the Co(II) precursor is

Recent advances in hypervalent iodine(III)-catalyzed functionalization of alkenes

• Xiang Li,
• Pinhong Chen and
• Guosheng Liu

Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154

• high yields [61]. Recently, Jacobsen and co-workers reported the stereoselective synthesis of syn-β-fluoroaziridine building blocks via a chiral aryl iodide-catalyzed fluorination of allylic amines (Scheme 11) [62]. On the basis of their previous work, the C2-symmetric aryl iodide 31 as a catalyst was

• ratio of amines and HF was important for obtaining reasonable yields. Indeed, excellent 19F NMR yields albeit lower isolated yields were obtained in this reaction (Scheme 12). In an attempt to induce enantioselectivity, the chiral aryl iodide derivative 39 only gave a moderate enantioselectivity (22% ee

• ). Meantime, a similar work was independently reported by Jacobsen and co-workers, in which the reactive iodoarene difluoride could be in situ generated by oxidation of aryl iodide 40 with mCPBA [64]. The reaction showed a wide substrate scope, with toleration of terminal, internal alkenes as well as electron

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• to afford 2 equivalents of the corresponding biphenyl products in nearly quantitative yields (Scheme 34). It is assumed that the first cross coupling reaction with the iodonium salt liberates an aryl iodide moiety, available for the second palladium-catalyzed coupling reaction. Three years later, the

• of aryl iodide. The latter is then used for a sequential ruthenium-catalyzed ortho-C–H functionalization directed by the pyrazole group (Scheme 37) [76]. Starting from non-symmetrical diaryl-λ3-iodanes, the electron-poorest or more sterically hindered aromatic group is first transferred to the 3,5

Three-component coupling of aryl iodides, allenes, and aldehydes catalyzed by a Co/Cr-hybrid catalyst

• Kimihiro Komeyama,
• Shunsuke Sakiyama,
• Kento Iwashita,
• Itaru Osaka and
• Ken Takaki

Beilstein J. Org. Chem. 2018, 14, 1413–1420, doi:10.3762/bjoc.14.118

• addition of an aryl iodide 1 to a low-valent cobalt species to form an arylcobalt species G that reacts with an allene 2 to stereoselectively generate an allylcobalt H via carbocobaltation. Rapid transmetalation between H and the chromium salt [8][9] triggers the transfer of the cobalt allyl group to the

Atom-economical group-transfer reactions with hypervalent iodine compounds

• Andreas Boelke,
• Peter Finkbeiner and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

• reagents. Even though these compounds are superior substrates in terms of reactivity and stability, their utilization is accompanied by stoichiometric amounts of an aryl iodide as waste. This highly nonpolar side product can be tedious to separate from the desired target molecules and significantly reduces

• generally preferred hypervalent iodine compounds for electrophilic group transfer reactions, during which the central iodine atom is transformed from a high energy hypervalent state into a normal valent state by a two-electron reduction. The high stability of the newly formed aryl iodide is the

• thermodynamic driving force for all λ3-iodane-mediated oxidative transformations. Even though this process guarantees the high reactivity of these reagents, it has one major obstacle: after the oxidation process, stoichiometric amounts of the aryl iodide are produced as waste. Aryl iodides, as nonpolar organic

A survey of chiral hypervalent iodine reagents in asymmetric synthesis

• Soumen Ghosh,
• Suman Pradhan and
• Indranil Chatterjee

Beilstein J. Org. Chem. 2018, 14, 1244–1262, doi:10.3762/bjoc.14.107

• displacement of the aryl iodide by the CO2R group in 77 leading to chiral lactones of type 78 [56]. Rearrangement strategy Wirth et al. used I(III) reagent 8b for the development of a stereoselective oxidative rearrangement method to synthesize α-arylated carbonyls 81 from α,β-unsaturated carbonyls 80 (Scheme

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• thiyl radical addition forms a [NiII] intermediate. A second single-electron reduction by [IrII] yields the respective [NiI] sulfide. After oxidative addition of the aryl iodide to the [NiI] sulfide complex, the respective C–S cross-coupling product is formed via reductive elimination from the [NiIII

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• isolated in analytically pure form from the reaction of the corresponding aryl iodide and Cl2, even though the nitro groups render the iodine atom less Lewis basic and thermodynamically less prone to oxidation. The Hammett σ values associated with CF2CF3 and CF2CF2CF3 substituents (σp 0.52; σm 0.47–0.52

• isolation of the dinitro-substituted aryliodine(III) dichloride II-Me in pure form (Scheme 1), but not the bis(perfluorohexyl) species 1,3,5-(Rf6)2C6H3ICl2 (Scheme 6, Figure 1). The latter is derived from a more Lewis basic aryl iodide, with Cl2 addition 0.83 kcal/mol more favorable. The ortho methyl group

Comparative profiling of well-defined copper reagents and precursors for the trifluoromethylation of aryl iodides

• Peter T. Kaplan,
• Jessica A. Lloyd,
• Mason T. Chin and
• David A. Vicic

Beilstein J. Org. Chem. 2017, 13, 2297–2303, doi:10.3762/bjoc.13.225

• over time are plotted graphically in Figure 1. As shown in Figure 1, conditions where the [(phen)CuCF3] was generated in situ (B2) provided the best yields of 4-(trifluoromethyl)-1,1’-biphenyl after 24 hours, with yields and conversion of aryl iodide (data not shown) both near 65%. When commercially

Synthesis of substituted Z-styrenes by Hiyama-type coupling of oxasilacycloalkenes: application to the synthesis of a 1-benzoxocane

• James R. Vyvyan,
• Courtney A. Engles,
• Scott L. Bray,
• Erik D. Wold,
• Christopher L. Porter and
• Mikhail O. Konev

Beilstein J. Org. Chem. 2017, 13, 2122–2127, doi:10.3762/bjoc.13.209

• the eight-membered ring. We endeavored to test the strategy through the preparation of a simplified model compound 1 (Figure 1). We envisaged the precursor to the cycloetherification, 2, would be prepared from the Hiyama-type cross-coupling of the appropriate aryl iodide 3 and the oxasilacycloalkene 4

• in moderate to excellent yields. When multiple halogens were present, high selectivity for reaction at the aryl iodide was observed (Table 1, entries 3–5). Pyridyl iodide 22 also worked well in the cross-coupling (Table 1, entry 8). Having prepared a number of substituted Z-styrenes, we next focused

Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2017, 13, 960–987, doi:10.3762/bjoc.13.97

• treatment of bipolar disorder and schizophrenia [10]. The process involves four reaction steps, one inline extraction, and a filtration step. The reaction is shown in Scheme 1. Initially, a Buchwald–Hartwig reaction is carried out between aryl iodide and aminothiazole. Pd2dba3 was used as a catalyst and

• will help to transform this synthesis to a process. Figure 3B shows the P&ID for the olanzapine manufacturing process. The flow rate of aryl iodide is fixed at a desired set point value using a control valve, which also helps to stop the pump in the case that the reaction temperature or pressure

• increase beyond a certain set-point over the subsequent reaction steps. The aminothiazole flow rate needs to be controlled using a ratio controller to maintain the molar ratio between aryl iodide and aminothiazole. Both of these streams can be preheated using a heat exchanger with a feedback controller

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• ) [36]. In this reaction system, non-toxic and cheap PEG-400 played a dual role as both ligand and solvent. The effective catalytic system could convert aryl iodide to phenols in high yields within 5 hours at 100 °C. The conversion of aryl bromides bearing either an electron-donating group or an

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

• David R. Chisholm,
• Garr-Layy Zhou,
• Ehmke Pohl,
• Roy Valentine and
• Andrew Whiting

Beilstein J. Org. Chem. 2016, 12, 1851–1862, doi:10.3762/bjoc.12.174

• %) according to GC–MS analysis, and the iodinated product 2 was difficult to isolate by chromatography. In light of these results, bromination was conducted with the aim of synthesising the corresponding aryl iodide 2 by halogen exchange (Scheme 3). After careful optimisation of the reaction conditions, the

Palladium-catalyzed picolinamide-directed iodination of remote ortho-C−H bonds of arenes: Synthesis of tetrahydroquinolines

• William A. Nack,
• Xinmou Wang,
• Bo Wang,
• Gang He and
• Gong Chen

Beilstein J. Org. Chem. 2016, 12, 1243–1249, doi:10.3762/bjoc.12.119

• −H functionalization reactions starting from readily accessible aryl iodide and alkylamine precursors (Scheme 1) [8]. Alkylpicolinamides were first subjected to Pd-catalyzed γ-C(sp3)−H arylation with aryl iodides to form γ-arylpropylpicolinamides [9][10][11][12][13][14][15][16][17][18][19][20]. These

Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups

• Jakub Saadi,
• Christoph Bentz,
• Kai Redies,
• Dieter Lentz,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2016, 12, 1236–1242, doi:10.3762/bjoc.12.118

• aryl iodide substituent were prepared following our well-established route via 2-siloxycyclopropane carboxylates D [6][7] that allows a regioselective introduction of the benzylic substituents at the α-carbon [8][9] to give intermediates E (Scheme 2). After fluoride-promoted ring opening [10] the

• rings was formed selectively from precursor 5a. We also briefly studied the palladium-catalyzed cyclization of p-methoxy-substituted aryl iodide 6a/b that led under the standard conditions to a mixture containing compound 16 (Scheme 7). We cannot exclude that other regioisomers or even primarily formed

• halides in the presence of the carbonyl compound is also known, e.g., the Barbier reaction employing magnesium. The related transformation described in this report very likely involves an arylpalladium species as nucleophile that is in situ generated from the aryl iodide moiety. Similar palladium

Conjugate addition–enantioselective protonation reactions

• James P. Phelan and
• Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

• optimal, providing the product with excellent enantioselectivity (Scheme 18c). Notably, the authors did not observe any side reaction between the palladium and aryl bromide or aryl iodide groups. Using NMR analysis and ESIMS Sodeoka and co-workers probed the mechanism of the reaction, observing a complex

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

• Takashi Nishikata,
• Alexander R. Abela,
• Shenlin Huang and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

• palladacycle; (2) reaction of the cationic palladacycle with an aryl iodide, arylboronic acid or acrylate, and (3) regeneration of the active cationic palladium catalyst. The reaction between a cationic palladium(II) complex and arylurea allowed the formation and isolation of the corresponding palladacycle

• ], those catalyzed by cationic palladium have been much less thoroughly examined. We hypothesized that our catalytic cycles for the Fujiwara–Moritani, arylboronic acid, and aryl iodide coupling reactions catalyzed by cationic palladium complexes are composed of three key steps; (1) aromatic C–H activation

• , run 9), Suzuki–Miyaura coupling (Scheme 4), and arylation with aryl iodide [121][122][150]. HBF4 apparently acts as an acetate scavenger to generate the active cationic palladium(II) species (Scheme 10). As discussed previously herein, there are several routes available for cyclopalladation and C–H