Three-component N-alkenylation of azoles with alkynes and iodine(III) electrophile: synthesis of multisubstituted N-vinylazoles

• Jun Kikuchi,
• Roi Nakajima and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2024, 20, 891–897, doi:10.3762/bjoc.20.79

• natural products and pharmaceutical agents, including antifungal drugs [1][2][3], and hence their selective preparation has attracted considerable attention from the synthetic community. Compared to methods for the de novo construction of azole heterocycles, direct functionalization of the azole N–H bond

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• active natural products. The direct functionalization of C–H bonds in enamides offers a convenient and versatile approach to access a wide range of functionalized enamides. In 2021, Fu and his colleagues successfully developed a novel method for the stereoselective alkylation of enamides 14 using iodine

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• of several methods for the synthesis of functionalized pyridines or their integration into an organic molecule, new methodologies for the direct functionalization of pyridine scaffolds have been developed during the past two decades. In addition, transition-metal-catalyzed C–H functionalization and

C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• furfural derivatives have been developed. In particular, their direct functionalization by transition-metal-catalyzed C–H activation processes [16][17][18] has become a major area of interest where only a few methods have been reported so far. Most examples concern functionalization at C5, which is the

• steps, and thus to consider the direct functionalization of furfural via the in-situ formation of furfurylimine. Furthermore, as the [Ru3(CO)11(PPh3)] comp4 catalyst showed an activity and a solubility in batch similar to comp1, we continued the optimization with the latter, triphenylphosphine being

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

• Louis Monsigny,
• Floriane Doche and
• Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

• [6][7][8][9][10][11]. Among them [2][5][12][13][14][15][16][17][18], the direct functionalization of a simple C–H bond by transition-metal catalysis [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] became an important tool offering new

Microelectrode arrays, electrosynthesis, and the optimization of signaling on an inert, stable surface

• Kendra Drayton-White,
• Siyue Liu,
• Yu-Chia Chang,
• Sakashi Uppal and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2022, 18, 1488–1498, doi:10.3762/bjoc.18.156

• of the molecules placed at those sites. In the majority of such studies, the molecules to be added to the electrodes in an array are attached directly to the array either through the use of a self-assembled monolayer or direct functionalization of a carbon electrode [12][13]. Following the synthetic

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• powerful role of molecular containers to achieve precise transformation of complex molecules. Oxidation C–H bonds are ubiquitously distributed in nearly all of the organic compounds, which makes them predominant candidates for the modification of complex molecules. Without pre-activation, direct

• functionalization of C–H bonds brings reaction economy and effectiveness. However, owing to the rifeness of the reactivity-similar C–H bonds, it is hard to achieve discriminate control over the product site-selectivity. In nature, the site-selective oxidation of C–H bonds is facilitated by enzymes with the donor

Photoredox catalysis in nickel-catalyzed C–H functionalization

• Lusina Mantry,
• Rajaram Maayuri,
• Vikash Kumar and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2021, 17, 2209–2259, doi:10.3762/bjoc.17.143

• products 39 with good regioselectivities. The authors proposed a tentative visible-light-driven radical chain mechanistic profile with nickel chain-walking as a key step to rationalize the C–H arylation process [78]. Alkylation The direct functionalization of C–H bonds in alkyl groups is a fundamental but

• has improved further the C–H acylation procedures by working under mild reaction conditions. Thus, Doyle and Joe reported a mild C–H acylation protocol for the direct functionalization of α-amino C(sp3)–H bonds of N-arylamines 1 with acyl electrophiles such as anhydrides 72 and 2-pyridyl thioester 73

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

Synthesis of β-triazolylenones via metal-free desulfonylative alkylation of N-tosyl-1,2,3-triazoles

• Soumyaranjan Pati,
• Renata G. Almeida,
• Eufrânio N. da Silva Júnior and
• Irishi N. N. Namboothiri

Beilstein J. Org. Chem. 2021, 17, 762–770, doi:10.3762/bjoc.17.66

• paved the way for further modification of the protocol (Scheme 1c). Direct functionalization of triazoles is an alternative strategy to access triazoles with the desired substitution pattern. However, such approaches are complicated by a low energy barrier between the N1 and N2 tautomers in solution

• -triazoles with alkynes and Rh catalysed N1 and N2 selective alkylations [24][25]. As for metal-free approaches, besides synthesizing N-alkylated triazoles via 1,3-dipolar cycloaddition of alkyl azide with enols generated from carbonyl compounds under transition metal-free conditions [26], a direct

• functionalization of triazoles under metal-free conditions has been reported. These include the Broensted acid-catalysed N2 alkylation [27], organocatalytic N1 alkylation [28][29], N2-arylation using hypervalent iodine (Scheme 1c) [30], N2-alkylation involving radical intermediate [31], pyridine-N-oxide-mediated N1

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• they are the most trustworthy strategies for direct functionalization of aromatic scaffolds [50]. As can be inspected from Scheme 18, monoiodosumanene 79 was obtained by gold-catalyzed iodination in the presence of N-iodosuccinimide (NIS). The mononitrosumanene 80 was achieved through the nitration

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

• directed ortho-metalation should exhibit visible-light absorption property and thus, under visible-light irradiation, the overall catalytic cycle could benefit from the photocatalytic activation. Following the initial hypothesis, the direct functionalization of phenylpyridine substrates turned out to be

• harvest visible light and triggers the expected transformation at room temperature. Undirected C–H activation In parallel to the development of the field of metal-catalyzed directed C–H activation, reactions involving the direct functionalization of simple aromatic compounds, depleted of a coordinating

In silico rationalisation of selectivity and reactivity in Pd-catalysed C–H activation reactions

• Liwei Cao,
• Mikhail Kabeshov,
• Steven V. Ley and
• Alexei A. Lapkin

Beilstein J. Org. Chem. 2020, 16, 1465–1475, doi:10.3762/bjoc.16.122

• developing machine learning models for predicting reaction outcomes. C–H activation reactions allow conversion of relatively inexpensive and abundant hydrocarbons into the more sophisticated value-added molecules [11]. With the notion of step-economical and environmentally friendly synthesis, direct

• functionalization of C–H bonds is a powerful strategy for the synthesis and derivatization of organic molecules [12]. Homogeneous catalysis employing transition metal complexes has been widely accepted as one of the most efficient ways to perform C–H activation-based synthesis with high selectivity under relatively

Copper catalysis with redox-active ligands

• Agnideep Das,
• Yufeng Ren,
• Cheriehan Hessin and
• Marine Desage-El Murr

Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77

• oxidation of alcohols and representative substrate scope. Introduction of H-bonding network in the ligand coordination sphere. Well-defined isatin copper complexes. Catalyst control in the biomimetic phenol ortho-oxidation. Structural diversity accessible by direct functionalization. Copper-catalyzed

Photocatalytic deaminative benzylation and alkylation of tetrahydroisoquinolines with N-alkylpyrydinium salts

• David Schönbauer,
• Carlo Sambiagio,
• Timothy Noël and
• Michael Schnürch

Beilstein J. Org. Chem. 2020, 16, 809–817, doi:10.3762/bjoc.16.74

• ] and pharmaceuticals [10][11]. Consequently, the direct functionalization of this scaffold has attracted significant interest in recent years. Even though many transformations have been realized via a cross-dehydrogenative coupling approach [12][13] (e.g., arylations [14][15], cyanomethylation [16

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

Six-fold C–H borylation of hexa-peri-hexabenzocoronene

• Mai Nagase,
• Kenta Kato,
• Akiko Yagi,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2020, 16, 391–397, doi:10.3762/bjoc.16.37

• , Nagoya, 464-8602, Japan 10.3762/bjoc.16.37 Abstract Hexa-peri-hexabenzocoronene (HBC) is known to be a poorly soluble polycyclic aromatic hydrocarbon for which direct functionalization methods have been very limited. Herein, the synthesis of hexaborylated HBC from unsubstituted HBC is described. Iridium

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

Regioselective (thio)carbamoylation of 2,7-di-tert-butylpyrene at the 1-position with iso(thio)cyanates

• Anna Wrona-Piotrowicz,
• Marzena Witalewska,
• Janusz Zakrzewski and
• Anna Makal

Beilstein J. Org. Chem. 2017, 13, 1032–1038, doi:10.3762/bjoc.13.102

• ; pyrene; thioamide; Introduction Direct functionalization of pyrene 1 has attracted a great deal of attention in recent years because it is the most straightforward route to novel organic molecular materials for optoelectronic devices (OLEDs, field-effect transistors, fluorescent sensors, dye lasers, etc

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

• intermediate, characterized by X-ray analysis. Roles of various additives in the stepwise process have also been studied. Keywords: arylation; cationic palladium; C–H functionalization; green chemistry; olefination; Introduction Transition metal-catalyzed, direct functionalization of aryl C–H bonds has made

Recent advances in C(sp³)–H bond functionalization via metal–carbene insertions

• Bo Wang,
• Di Qiu,
• Yan Zhang and
• Jianbo Wang

Beilstein J. Org. Chem. 2016, 12, 796–804, doi:10.3762/bjoc.12.78

• –carbene; site-selectivity; Introduction Direct functionalization of inactivated C–H bonds, especially C(sp3)–H bonds, have attracted significant attentions in recent years. The C(sp3)–H bond activation strategies based on radical reactions and transition metal catalysis have been explored, alongside the

Iridium/N-heterocyclic carbene-catalyzed C–H borylation of arenes by diisopropylaminoborane

• Mamoru Tobisu,
• Takuya Igarashi and
• Naoto Chatani

Beilstein J. Org. Chem. 2016, 12, 654–661, doi:10.3762/bjoc.12.65

• borylation; iridium; N-heterocyclic carbene; Introduction Catalytic C–H borylation of arenes has become an essential tool in organic synthesis [1]. The eminent features of this methodology include 1) no directing group is needed, allowing the direct functionalization of simple arenes; 2) the

Recent advances in copper-catalyzed C–H bond amidation

• Jie-Ping Wan and
• Yanfeng Jing

Beilstein J. Org. Chem. 2015, 11, 2209–2222, doi:10.3762/bjoc.11.240

• ideal model of modern organic synthesis, the direct functionalization of inactivated C–H bonds has been proved to be a promising tool to enable atom and step economical synthesis. Inspired by the splendid advances that have taken place in the chemistry of C–H activation, the synthesis of amides has

Lewis acid-catalyzed redox-neutral amination of 2-(3-pyrroline-1-yl)benzaldehydes via intramolecular [1,5]-hydride shift/isomerization reaction

• Chun-Huan Jiang,
• Xiantao Lei,
• Le Zhen,
• Hong-Jin Du,
• Xiaoan Wen,
• Qing-Long Xu and
• Hongbin Sun

Beilstein J. Org. Chem. 2014, 10, 2892–2896, doi:10.3762/bjoc.10.306

• used for the activation of C–H bonds [11][12][13][14][15][16][17][18]. Among the reported transformations, intramolecular redox processes based on direct functionalization of C(sp3)–H bonds linking with α heteroatoms are useful for the synthesis of structurally diverse amines and ether derivatives [19

Exploration of C–H and N–H-bond functionalization towards 1-(1,2-diarylindol-3-yl)tetrahydroisoquinolines

• Michael Ghobrial,
• Marko D. Mihovilovic and
• Michael Schnürch

Beilstein J. Org. Chem. 2014, 10, 2186–2199, doi:10.3762/bjoc.10.226

• wanted to use direct functionalization either via C–H activation or cross dehydrogenative coupling for C–C-bond-forming reactions avoiding the use of two prefunctionalized building blocks. Naturally, C–N-bond formation should proceed via Buchwald–Hartwig coupling. The target molecules can be considered