Controlling alkyne reactivity by means of a copper-catalyzed radical reaction system for the synthesis of functionalized quaternary carbons

• Goki Hirata,
• Yu Yamane,
• Naoya Tsubaki,
• Reina Hara and
• Takashi Nishikata

Beilstein J. Org. Chem. 2020, 16, 502–508, doi:10.3762/bjoc.16.45

• base other than Cs2CO3, a decreased yield of 3a was observed. Finally, an increased amount of catalyst was effective for obtaining the highest yield (Table 1, entry 9). The total yield was moderate, but the yields for each step of this two-step tandem reaction system (ATRA followed by Castro–Stephens

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

• trace of final product, whereas the reaction was not completed with (E)-but-2-enal (entry 17 and 18, Table 1). Wang et al. have developed a Cu(II)-catalyzed tandem reaction between ketonic pyridine 90 and benzylamine 91 using DMF as a solvent at 110 °C, in the presence of oxygen as a clean oxidant

• which underwent resonance to give 94. This was followed by intramolecular amination, oxidative dehydrogenation, and rearrangement to yield the final product 37 (Scheme 31). A one-pot, tandem reaction promoted by a I2/CuO system to synthesize imidazo[1,2-a]pyridines was reported by Cai et al. (Scheme 32

Ring-closing-metathesis-based synthesis of annellated coumarins from 8-allylcoumarins

• Christiane Schultze and
• Bernd Schmidt

Beilstein J. Org. Chem. 2018, 14, 2991–2998, doi:10.3762/bjoc.14.278

• application of sequential one-pot transformations and motivated by the relevance of prenylated and other substituted coumarins in natural products and medicinal chemistry, we [27][28][29] and others [30] have investigated a microwave-promoted tandem reaction for the synthesis of 8-substituted coumarins over

Copper(I)-catalyzed tandem reaction: synthesis of 1,4-disubstituted 1,2,3-triazoles from alkyl diacyl peroxides, azidotrimethylsilane, and alkynes

• Muhammad Israr,
• Changqing Ye,
• Munira Taj Muhammad,
• Yajun Li and
• Hongli Bao

Beilstein J. Org. Chem. 2018, 14, 2916–2922, doi:10.3762/bjoc.14.270

Synthesis of indole–cycloalkyl[b]pyridine hybrids via a four-component six-step tandem process

• Muthumani Muthu,
• Rakkappan Vishnu Priya,
• Abdulrahman I. Almansour,
• Raju Suresh Kumar and
• Raju Ranjith Kumar

Beilstein J. Org. Chem. 2018, 14, 2907–2915, doi:10.3762/bjoc.14.269

• -yl)-3-oxopropanenitrile; tandem reaction; Introduction The syntheses of novel heterocycles through greener protocols have received a great deal of attention of the synthetic organic chemists in view of environmental concerns [1][2][3]. The multicomponent tandem/domino reaction is one among several

• ]. Recently we reported the synthesis of pyridine/benzo-fused cyclododecanes through a four-component tandem reaction [70]. In continuation we herein report the synthesis of novel indole substituted cycloalkyl[b]pyridine-3-carbonitriles from a one-pot six-step tandem protocol involving 3-(1H-indol-3-yl)-3

• multistep tandem reaction afforded 7f in 93% yield involving the formation of two new C–N and C–C bonds in a single transformation without the need to isolate or purify the intermediates. Furthermore, the above reaction occurred stereoselectively to afford indole–cyclododeca[b]pyridine-3-carbonitrile 7f

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• presence of the O–H stretching of the -SO3H group at 2650–3550 cm−1 as well as the vibrational modes of N–SO2 and O–SO2 bonds at 1062 cm−1 and 1179 cm−1, respectively. The catalyst 3 was found to be effective in the tandem reaction between β-naphthol (23), aromatic aldehydes 7, and amide derivatives 49 at

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

• (trifluoroacetoxy)iodo]arene. Catalytic nitrene additions mediated by [bis(acyloxy)iodo]arenes. Tandem of C(sp3)–H amination/sila-Sonogashira–Hagihara coupling. Tandem reaction using a λ3-iodane as an oxidant, a substrate and a coupling partner. Synthesis of 1,2-diarylated acrylamidines with ArI(OAc)2

Metal-free formal synthesis of phenoxazine

• Gabriella Kervefors,
• Antonia Becker,
• Chandan Dey and
• Berit Olofsson

Beilstein J. Org. Chem. 2018, 14, 1491–1497, doi:10.3762/bjoc.14.126

• recovered starting material was 96%. The limited conversion into product 2 complicated our aim to perform the arylation and cyclization in one pot. The tandem reaction set up depicted in Scheme 6b delivered the O-arylated 3 in 87% yield, rather than product 2, further illustrating the sensitivity of the

Methyl isocyanide as a convertible functional group for the synthesis of spirocyclic oxindole γ-lactams via post-Ugi-4CR/transamidation/cyclization in a one-pot, three-step sequence

• Amarendar Reddy Maddirala and
• Peter R. Andreana

Beilstein J. Org. Chem. 2018, 14, 875–883, doi:10.3762/bjoc.14.74

• transformations involving tandem reaction sequences [3] and the Ugi–deprotection–cyclization (UDC) strategies [4][5][6][7][8] have been exploited as powerful tools allowing access to biological and pharmaceutical high-value heterocyclic scaffolds [9][10][11]. These reactions are appealing in that they are atom

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• conversion of glucose in a tandem reaction [82]. The hydrophilic block of their polymersomes was PEG, and the hydrophobic block contained both poly[2-(diethylamino)ethyl methacrylate] (PDEAEM) which is pH responsive, and poly[4-(3,4-dimethylmaleimido)butyl methacrylate] (PDMIBM) as cross-linker. The activity

Solvent-free and room temperature synthesis of 3-arylquinolines from different anilines and styrene oxide in the presence of Al₂O₃/MeSO₃H

• Hashem Sharghi,
• Mahdi Aberi,
• Mohsen Khataminejad and
• Pezhman Shiri

Beilstein J. Org. Chem. 2017, 13, 1977–1981, doi:10.3762/bjoc.13.193

• , expensive catalyst and low regioselectivity in some cases. One current area of modern synthetic organic chemistry is the development of powerful and effective practical procedures that minimize the requisite time, temperature, labour, and cost for the desired transformations [12][13]. The tandem reaction of

An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

• Carolina S. García,
• Paula M. Uberman and
• Sandra E. Martín

Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166

• : 10 min; 2º cycle: 20 min; 3º cycle: 30 min, 4º cycle: 30 min, 5º cycle: 30 min. Synthesis of (E)-pterostilbene (19) catalyzed by PVP-Pd NPs. Reaction condition optimizations.a Mizoroki–Heck reaction of aryl halides with olefins catalyzed by PVP-Pd NPs.a Stille–Heck tandem reaction of aryl halides

Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds

• Santanu Hati,
• Ulrike Holzgrabe and
• Subhabrata Sen

Beilstein J. Org. Chem. 2017, 13, 1670–1692, doi:10.3762/bjoc.13.162

• (Scheme 24). Ruthenium catalysts have also been used under aerobic conditions for oxidative dehydrogenation of heterocycles. For example Lingayya et al. demonstrated that ruthenium chloride (p-cumene)2 [RuCl2(p-cumene)2] catalyzed tandem reaction involving oxidative dehydrogenation, cross coupling and

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• in 98% yield for both THP and MOM ethers (Scheme 62). Irradiation of aromatic γ,δ-epoxy ketones 226 with a medium-pressure UV mercury lamp (450 W) led to the formation of 1-indanones 227 via a photochemical epoxy rearrangement and 1,5-biradical cyclization tandem reaction (Scheme 63) [92]. The best

Synthesis of structurally diverse 3,4-dihydropyrimidin-2(1H)-ones via sequential Biginelli and Passerini reactions

• Andreas C. Boukis,
• Baptiste Monney and
• Michael A. R. Meier

Beilstein J. Org. Chem. 2017, 13, 54–62, doi:10.3762/bjoc.13.7

• the Passerini reaction for the first time in a sequential multicomponent tandem reaction approach. After evaluation of all possible linker components and a suitable solvent system, highly functionalized dihydropyrimidone–α-acyloxycarboxamide compounds were obtained in good to excellent yields. In a

• reactions, a large number of structurally diverse compounds could be synthesized. In addition, a one-pot Biginelli–Passerini tandem reaction was demonstrated. All products were carefully characterized via 1D and 2D NMR as well as IR and HRMS. Keywords: Biginelli reaction; molecular diversity

• interlink both the Biginelli and the Passerini reaction). In the earlier reported Biginelli–Ugi tandem reaction of Wipf et al. [36], methanol was used as solvent. As mentioned previously, the solvent of choice for the Passerini reaction is dichloromethane, providing the highest yields. The DHMP Biginelli

Application of heterocyclic aldehydes as components in Ugi–Smiles couplings

• Katelynn M. Mason,
• Michael S. Meyers,
• Abbie M. Fox and
• Sarah B. Luesse

Beilstein J. Org. Chem. 2016, 12, 2032–2037, doi:10.3762/bjoc.12.191

• also a competent component for Ugi–Smiles adduct formation. Keywords: Diels–Alder cycloaddition; epoxyisoindoline; multicomponent coupling reaction; tandem reaction; Ugi–Smiles coupling; Introduction Synthetic methods to efficiently prepare libraries of biologically-relevant compounds are in demand

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• amines 117. A CuI-catalyzed three-component tandem reaction of 2-(2-formylphenyl)ethanones 120, aromatic amines 121, and diethyl phosphonate leading to 1,2-dihydroisoquinolin-1-ylphosphonates 123 has been reported by Wu et al. (Scheme 26) [52]. This reaction proceeds via the imine intermediate 122

• synthesis of N-arylisoquinolone-1-phosphonates 119. CuI-catalyzed three-component tandem reaction of 2-(2-formylphenyl)ethanones with aromatic amines and diethyl phosphonate. Synthesis of 1,5-benzodiazepin-2-ylphosphonates via ytterbium chloride-catalyzed three-component reaction. FeCl3-catalyzed four

1H-Imidazol-4(5H)-ones and thiazol-4(5H)-ones as emerging pronucleophiles in asymmetric catalysis

• Antonia Mielgo and
• Claudio Palomo

Beilstein J. Org. Chem. 2016, 12, 918–936, doi:10.3762/bjoc.12.90

• two other examples (Scheme 7b), however, rhodanines of type 45 have been employed to produce spirocyclic compounds. The first case is an enamine/Michael tandem reaction to unsaturated enones [81] (Scheme 7b,1) and the second one is the Diels–Alder reaction with 2,4-dienals which occurs via trienamine

Scope and mechanism of the highly stereoselective metal-mediated domino aldol reactions of enolates with aldehydes

• M. Emin Cinar,
• Bernward Engelen,
• Martin Panthöfer,
• Hans-Jörg Deiseroth,
• Jens Schlirf and
• Michael Schmittel

Beilstein J. Org. Chem. 2016, 12, 813–824, doi:10.3762/bjoc.12.80

• ][10][11], stereoselective syntheses [12][13][14][15][16], and tandem reactions [17][18][19]. While the latter processes usually comprise only one aldol reaction, tandem reaction sequences containing two consecutive aldol steps are mostly limited to the trimerization of enolates [20][21][22]. Metal

(Thio)urea-mediated synthesis of functionalized six-membered rings with multiple chiral centers

• Giorgos Koutoulogenis,
• Nikolaos Kaplaneris and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2016, 12, 462–495, doi:10.3762/bjoc.12.48

• 2009, the first asymmetric tandem reaction for the construction of bicyclic skeletons utilizing a secondary amine-thiourea was reported (Scheme 14) [25]. In this reaction, (E)-2-nitroallyl acetates 40 were used, that could serve as reagents, which can install a nitro group into the final product. After

A concise and efficient synthesis of benzimidazo[1,2-c]quinazolines through CuI-catalyzed intramolecular N-arylations

• Xinlong Pang,
• Chao Chen,
• Ming Li and
• Chanjuan Xi

Beilstein J. Org. Chem. 2015, 11, 2365–2369, doi:10.3762/bjoc.11.258

• -cyanoaniline (1) and diaryliodonium salts 2 based on our previously published method [13][14] (Scheme 1). Results and Discussion During the study of the synthesis of various carbocycles or heterocycles with copper catalysts [13][14][15][16][17], we found an interesting tandem reaction of o-cyanoanilines 1 and

Tandem cross enyne metathesis (CEYM)–intramolecular Diels–Alder reaction (IMDAR). An easy entry to linear bicyclic scaffolds

• Javier Miró,
• María Sánchez-Roselló,
• Álvaro Sanz,
• Fernando Rabasa,
• Carlos del Pozo and
• Santos Fustero

Beilstein J. Org. Chem. 2015, 11, 1486–1493, doi:10.3762/bjoc.11.161

• reaction; tandem reaction; Introduction Among all metathetic processes, the enyne metathesis reaction has received significant attention as an attractive and frequently used synthetic tool in organic synthesis [1][2][3][4][5][6][7]. It is an atom economical process that combines alkene and alkyne moieties

Synthesis of alpha-tetrasubstituted triazoles by copper-catalyzed silyl deprotection/azide cycloaddition

• Zachary L. Palchak,
• Paula T. Nguyen and
• Catharine H. Larsen

Beilstein J. Org. Chem. 2015, 11, 1425–1433, doi:10.3762/bjoc.11.154

• -deprotection with azide–alkyne cycloaddition, producing hindered triazoles in 6 hours. This tandem reaction was optimal with a copper(II) triflate and sodium ascorbate (NaAsc) as a mild reductant. The outcome that copper(II) triflate provides the highest yields for the one-pot deprotection/click reaction was

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• phenanthridine (Scheme 20) [44]. The synthesis by multicomponent tandem reaction/carbocyclization starts with the formation of a 4-aryl-3-arylethynylisoquinoline from 2-bromobenzaldehyde/tert-butylamine/1,3-diyne. The second (in situ) step is based on the ring closure, either via gold/silver-catalysed

Synthesis of 2-trifluoromethylpyrazolo[5,1-a]isoquinolines via silver triflate-catalyzed or electrophile-mediated one-pot tandem reaction

• Xiaoli Zhou,
• Meiling Liu,
• Puying Luo,
• Yingjun Lai,
• Tangtao Yang and
• Qiuping Ding

Beilstein J. Org. Chem. 2014, 10, 2286–2292, doi:10.3762/bjoc.10.238

• annulation of N’-(2-alkynylbenzylidene)hydrazides followed by an 1,3-dipolar cycloaddition. Results and Discussion Based on Wu’s work on the silver triflate-catalyzed tandem reaction of N’-(2-alkynylbenzylidene)hydrazides with dimethyl acetylenedicarboxylate [28], we started our research by examining the

• -alkynylbenzylidene)hydrazides 1, electrophiles (I2 or ICl), and ethyl 4,4,4-trifluorobut-2-ynoate (2) were carried out under mild conditions. The results are summarized in Table 3. For all cases, this tandem reaction worked well leading to the corresponding iodinated fluorine-containing pyrazolo[5,1-a]isoquinolines

• mode on a Bruker mass spectrometer. General procedure for the silver triflate-catalyzed one-pot tandem reaction of N’-(2-alkynylbenzylidene)hydrazide 1 with ethyl 4,4,4-trifluorobut-2-ynoate 2: A mixture of N’-(2-alkynylbenzylidene)hydrazide 1 (0.30 mmol, 1.0 equiv) and silver triflate (5 mol %) in