Carbonylative synthesis and functionalization of indoles

• Alex De Salvo,
• Raffaella Mancuso and
• Xiao-Feng Wu

Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87

• -Str. 29a, 18059 Rostock, Germany Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023 Liaoning, China 10.3762/bjoc.20.87 Abstract Carbonylation processes have become widely recognized as a versatile, convenient, and low-cost method for

• recent achievements on the synthesis and functionalization of indole derivatives via carbonylative approaches. Keywords: carbonylation; functionalization; indole; metal catalyst; organometallic chemistry; Introduction Indole is a heterocyclic compound consisting of a benzene ring fused with a pyrrole

• 1883 and involves its synthesis from phenylhydrazine and an aldehyde or ketone using an appropriate acid catalyst [8]. In the following years, new processes were developed for the synthesis of indole such as the Castro, Bischler, and Larock synthesis etc. [2][9][10]. Carbonylation reactions represent a

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• carried out with Cu. The aminocarbonylation reaction which was introduced by Schoenberg and Heck in 1974 is an efficient catalytic route to carboxamides [11]. It was a major step forward and has been amply applied in a number of carbonylation reactions over the years [12]. In 2011, Buchwald and

• driving forces for the development of the work discussed in this report. Results and Discussion Synthesis of o-(2-bromophenyl)aminoaniline via Buchwald–Hartwig C–N coupling One-pot synthesis of dibenzodiazepinones Our preliminary attempt to synthesize DBDAPs via B–H amination and carbonylation was carried

Sequential hydrozirconation/Pd-catalyzed cross coupling of acyl chlorides towards conjugated (2E,4E)-dienones

• Benedikt Kolb,
• Daniela Silva dos Santos,
• Sanja Krause,
• Anna Zens and
• Sabine Laschat

Beilstein J. Org. Chem. 2023, 19, 176–185, doi:10.3762/bjoc.19.17

• example, the sequential hydrozirconation/carbonylation of propargylic ethers 18 reported by Donato [58] yielded α,β-unsaturated lactones 19. Beside the hydrozirconation/acylation sequence of nitriles utilizing acid chlorides published by Majoral/Floreancig [59][60], Cox revealed that terminal alkynes 16

Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

• Yi Liu,
• Puying Luo,
• Yang Fu,
• Tianxin Hao,
• Xuan Liu,
• Qiuping Ding and
• Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

• structural motifs to provide the functionalized pyridine and pyrrole derivatives. The functionalization reactions cover iodination, bromination, trifluoromethylation, azidation, carbonylation, arylation, alkylation, selenylation, sulfenylation, amidation, esterification, and hydroxylation. We also briefly

• functionalizations of pyrrole derivatives, such as iodination, bromination, trifluoromethylation, azidation, carbonylation, arylation, and alkylation. The proposed mechanism generally involves two kinds of intramolecular cyclizations: one is 6-endo-dig cyclization to promote the formation of pyridine ring

Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• furylmercurials 91 via syn-addition of acetylene, which on carbonylation yielded the furan-containing carbonyl compound 92 (Scheme 30) [83]. It was proposed that initially mercuration of acetylene bonds via mercurinium like ions or π-complex takes place. Then the structure was stabilized through hydrogen bonding

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

Unexpected rearrangements and a novel synthesis of 1,1-dichloro-1-alkenones from 1,1,1-trifluoroalkanones with aluminium trichloride

• Beatrice Lansbergen,
• Catherine S. Meister and
• Michael C. McLeod

Beilstein J. Org. Chem. 2021, 17, 404–409, doi:10.3762/bjoc.17.36

• trichloride; dichloroalkenes; Friedel–Crafts alkylation; rearrangement; trifluoroalkanes; Introduction 1,1-Dichloro-1-alkenes are valuable synthetic intermediates and have been employed in Pd-mediated cross couplings of one or both chlorine atoms [1][2][3][4][5][6][7], carbonylation reactions [8], and C–H

¹⁹F NMR as a tool in chemical biology

• Diana Gimenez,
• Aoife Phelan,
• Cormac D. Murphy and
• Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• , carbanion, and radical chemistry. Furthermore, gem-difluorocyclopropanes readily go through carbonylation, dehalogenation, and annulation, resulting in various useful materials. 2.1 Thermal rearrangements The substitution of hydrogen with fluorine in cyclopropane leads to a significant weakening of the C–C

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

• Esra Demir,
• Ozlem Sari,
• Yasin Çetinkaya,
• Ufuk Atmaca,
• Safiye Sağ Erdem and
• Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

• oxazolidinones and five-membered cyclic carbonates of various structures. The most well-known strategies for the synthesis of oxazolidinones are the reaction of an amino alcohol with phosgene [5][22], the carbonylation reaction of β-amino alcohols with CO2 or dialkyl carbonates [23][24][25][26][27], the

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• ) intermediate occurs prior to the one-electron oxidation by the photoexcited catalyst. This contribution inspired also other research groups to investigate synergistic catalyses using Pd-based C–H catalysts. In 2016, Lei’s group reported the aerobic intramolecular oxidative carbonylation of enamides for the

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• ) [36]. The authors hypothesized that the C–O bond cleavage could be achieved via cobalt-mediated alcohol carbonylation followed by radical decarboxylation of the alkoxycarbonyl intermediate. In a proof-of-concept study, they proceeded with the carbonylation of 1-phenylethanol using Co(II) tetrakis(4

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

• of China, Beijing 100872, China 10.3762/bjoc.16.61 Abstract The reductive carbonylation of aryl iodides to aryl aldehydes possesses broad application prospects. We present an efficient and facile Rh-based catalytic system composed of the commercially available Rh salt RhCl3·3H2O, PPh3 as phosphine

• ligand, and Et3N as the base, for the synthesis of arylaldehydes via the reductive carbonylation of aryl iodides with CO and H2 under relatively mild conditions with a broad substrate range affording the products in good to excellent yields. Systematic investigations were carried out to study the

• pressure, cheap ligand and low metal dosage could significantly improve the practicability in both chemical researches and industrial applications. Keywords: cost-effective ligand; industrial catalysis; reductive carbonylation; rhodium catalyst; syngas; Introduction The exploration of environmentally

Visible-light-induced addition of carboxymethanide to styrene from monochloroacetic acid

• Kaj M. van Vliet,
• Nicole S. van Leeuwen,
• Albert M. Brouwer and
• Bas de Bruin

Beilstein J. Org. Chem. 2020, 16, 398–408, doi:10.3762/bjoc.16.38

• useful for the formation of new C–C bonds. Previous works from our group presented cobalt-catalyzed radical cyclization and carbonylation reactions [12][13][14][15][16]. Photoredox catalysis provides a way to generate radical intermediates from simple organic molecules by single-electron redox processes

A review of the total syntheses of triptolide

• Xiang Zhang,
• Zaozao Xiao and
• Hongtao Xu

Beilstein J. Org. Chem. 2019, 15, 1984–1995, doi:10.3762/bjoc.15.194

• -phenylethylamine (49) to generate key tricyclic intermediates 51 and 52, a Pd(II)-catalyzed carbonylation–lactonization reaction of 9 to construct the butenolide (D-ring), and a Friedel–Crafts isopropylation to install the C-13 isopropyl group. Still, the construction of the C-5 trans junction A-/B-ring was

• conversion of 89 to vinyl triflate 90, followed by reduction and palladium-catalyzed carbonylation–lactone formation to give key intermediate 8 [75][76][77]. After that, the three successive epoxides were installed by known procedures with some modification. The highlights were the introduction of the second

• and its relatives from commercially available acid 32 (Figure 2, route J and Scheme 8) [46]. This synthesis highlights the utilization of an indium(III)-catalyzed cationic polycyclization of 17 and a palladium-catalyzed carbonylation–in situ lactone formation to construct the key intermediate 94

Vicinal difunctionalization of alkenes by four-component radical cascade reaction of xanthogenates, alkenes, CO, and sulfonyl oxime ethers

• Shuhei Sumino,
• Takahide Fukuyama,
• Mika Sasano,
• Ilhyong Ryu,
• Antoine Jacquet,
• Frédéric Robert and
• Yannick Landais

Beilstein J. Org. Chem. 2019, 15, 1822–1828, doi:10.3762/bjoc.15.176

• tributyltin radical with 1a. The electrophilic α-carbonyl radical A does not react with CO even at high CO pressure [6], and therefore selectively adds to electron-rich olefin 2a to form a carbon-centered radical B. The radical B, regarded as a nucleophilic radical, then undergoes radical carbonylation with

• radical which sustains the radical chain. Since radical B can also add to sulfonyl oxime ether 3a, we used high CO pressure conditions to encourage the radical carbonylation to form acyl radical C. Conclusion In summary, we demonstrated that a four-component radical cascade reaction, between xanthogenates

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

• catalyst in acetonitrile, and a high pressure of both, CO and air, are needed in order to perform an oxidative carbonylation on 2-ethynylbenzamide 21. Up to ten compounds were obtained with yields ranging from 65 to 96%. Butyl, phenyl, benzyl or absence of substitution on the amide nitrogen produced, in

• transformation implies initial formation of an alkynylpalladium intermediate 25 followed by carbonylation to render acylpalladium 26 (Scheme 6). Reductive substitution of palladium by amine 22 furnishes diamide derivative 27 and Pd(0), which is reoxidized to Pd(II) again by HI and oxygen. Then, intramolecular

• -catalysed carbonylation of iodoarylimine 100 to produce acid chloride 102 (Scheme 29). Intramolecular nucleophilic attack of the imine onto the acyl chloride would furnish cyclic N-acyliminium derivative 103, which can then undergo a second palladium-catalysed carbonylation to form a stabilized ketene 104

Oxidative radical ring-opening/cyclization of cyclopropane derivatives

• Yu Liu,
• Qiao-Lin Wang,
• Zan Chen,
• Cong-Shan Zhou,
• Bi-Quan Xiong,
• Pan-Liang Zhang,
• Chang-An Yang and
• Quan Zhou

Beilstein J. Org. Chem. 2019, 15, 256–278, doi:10.3762/bjoc.15.23

• alkylidenecyclopropanes 1 with allylic bromides 78 for the synthesis of 2-bromo-1,6-dienes 79 via radical ring-opening and SH2’ reactions (path V in Scheme 17) [95]. The experimental results suggested that radical carbonylation could also be incorporated in the reaction sequence, leading to 2-bromo-1,7-dien-5-ones 80

Hydroarylations by cobalt-catalyzed C–H activation

• Rajagopal Santhoshkumar and
• Chien-Hong Cheng

Beilstein J. Org. Chem. 2018, 14, 2266–2288, doi:10.3762/bjoc.14.202

• activation. In 1941, Kharasch and Fields applied a cobalt salt as the catalyst for the homocoupling of Grignard reagents [28]. After 15 years, Murahashi discovered a cobalt-catalyzed chelation-assisted ortho C–H carbonylation of azobenzene and imines as the preliminary example of directing group assisted C–H

• C–H carbonylation. Hydroarylation by C–H activation. Pathways for cobalt-catalyzed hydroarylations. Co-catalyzed hydroarylation of alkynes with azobenzenes. Co-catalyzed hydroarylation of alkynes with 2-arylpyridines. Co-catalyzed addition of azoles to alkynes. Co-catalyzed addition of indoles to

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

• ]. Oxyarylation of alkenes [71]. Asymmetric oxidative rearrangements of alkenes [72]. Bromolactonization of alkenes [75]. Bromination of alkenes [77][78]. Cooperative strategy for the carbonylation of alkenes [79]. Acknowledgements We are grateful for financial support from the National Nature Science Foundation

Synthesis and stability of strongly acidic benzamide derivatives

• Frederik Diness,
• Niels J. Bjerrum and
• Mikael Begtrup

Beilstein J. Org. Chem. 2018, 14, 523–530, doi:10.3762/bjoc.14.38

• ][32][33]. Finally, two examples of syntheses via palladium-catalyzed carbonylation of trifluoromethanesulfonamide (1) have been reported [34][35]. The N-triflylbenzamides have only been explored as substrates in a few reactions. A recent report describes using N-triflylbenzamide as a directing group

Difunctionalization of alkenes with iodine and tert-butyl hydroperoxide (TBHP) at room temperature for the synthesis of 1-(tert-butylperoxy)-2-iodoethanes

• Hao Wang,
• Cui Chen,
• Weibing Liu and
• Zhibo Zhu

Beilstein J. Org. Chem. 2017, 13, 2023–2027, doi:10.3762/bjoc.13.200

• dioxygenation [10][11], dihydroxylation [10][12], bisperoxidation [13], oxyamidation [14], aminohydroxylation [15], oxyphosphorylation [16], deamination [17] and carbonylation–peroxidation [18]. Several very recent reports have pertained to metal-free catalysts for difunctionalization of alkenes such as UV

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• by Ube Industries [59]. The EniChem process involved an oxidative carbonylation of methanol, i.e., the reaction of methanol with carbon monoxide and oxygen catalyzed by cuprous chloride, while the Ube process used an oxidative carbonylation of methanol via methyl nitrite using NOx as oxidant, instead

Flow carbonylation of sterically hindered ortho-substituted iodoarenes

• Carl J. Mallia,
• Gary C. Walter and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2016, 12, 1503–1511, doi:10.3762/bjoc.12.147

• via a reverse “tube-in-tube” flow reactor at elevated pressures to give yields of carboxylated products that are much higher than those obtained under normal batch conditions. Keywords: carbon monoxide; carbonylation of ortho-substituted substrates; flow chemistry; gases in flow; “tube-in-tube

• ”; Introduction Carbonylation reactions have received a great deal of attention both in batch as well as in flow (using plug/annular flow reactors [1][2][3][4][5] or “tube-in-tube” reactors [6][7][8][9][10]) and generally produce the desired products in good yields [11][12][13][14]. This is not the case though

• for the carbonylation of ortho-substituted substrates which are much more challenging as highlighted by the limited literature precedence [15][16][17]. However, these products are of considerable industrial importance, especially the amide and ester derivatives, which are commonly found in