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

• reaction. Ghosh, Dhara et al. also reported a synthesis of substituted phenanthridines based on palladium-mediated Suzuki coupling (Scheme 14) [34][35]. Aerobic ligand-free domino Suzuki coupling–Michael addition reaction in the presence of Pd(OAc)2 and K3PO4 as a catalytic system in H2O was catalysed by

One-pot four-component reaction for convenient synthesis of functionalized 1-benzamidospiro[indoline-3,4'-pyridines]

• Chao Wang,
• Yan-Hong Jiang and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2014, 10, 2671–2676, doi:10.3762/bjoc.10.281

• generation of Huisgen’s 1,4-dipoles are aromatic heterocycles such as N-alkylimidazole, pyridine, quinoline, isoquinoline and primary aromatic amines. In recent years, other nitrogen-containing nucleophiles such as hydrazine and arylhydrazines are also used to generate Huisgen’s 1,4-dipoles in domino

Preparation of neuroprotective condensed 1,4-benzoxazepines by regio- and diastereoselective domino Knoevenagel–[1,5]-hydride shift cyclization reaction

• László Tóth,
• Yan Fu,
• Hai Yan Zhang,
• Attila Mándi,
• Katalin E. Kövér,
• Tünde-Zita Illyés,
• Attila Kiss-Szikszai,
• Balázs Balogh,
• Tibor Kurtán,
• Sándor Antus and
• Péter Mátyus

Beilstein J. Org. Chem. 2014, 10, 2594–2602, doi:10.3762/bjoc.10.272

• Chemistry, University of Debrecen, H-4010 Debrecen, Hungary Porfirin Ltd., Mikszáth K. u. 7. III/3, 4032 Debrecen, Hungary 10.3762/bjoc.10.272 Abstract Condensed O,N-heterocycles containing tetrahydro-1,4-benzoxazepine and tetrahydroquinoline moieties were prepared by a regio- and diastereoselective domino

• cellular injuries in human neuroblastoma SH-SY5Y cells in the range of those of positive controls. Keywords: 1,4-benzoxazepine; diastereoselective domino Knoevenagel–[1,5]-hydride shift cyclization; neuroprotective; tert-amino effect; TDDFT-ECD calculation; Introduction The 1,4-benzoxazepine structural

• neuroprotective condensed 2-phenyl-1,4-benzoxazepines rac-7a,b through the diastereoselective domino Knoevenagel–1,5-hydride shift cyclization reaction rac-5→rac-7a,b from the readily available 4-aryl-2-phenyl-1,4-benzoxazepine derivative, rac-5 (Scheme 1). Ring-closure transformations involving C(sp3)–H bond

Versatile synthesis of amino acid functionalized nucleosides via a domino carboxamidation reaction

• Vicky Gheerardijn,
• Jos Van den Begin and
• Annemieke Madder

Beilstein J. Org. Chem. 2014, 10, 2566–2572, doi:10.3762/bjoc.10.268

• -intermediates in DNA- and RNAzymes via an efficient and straightforward domino carboxamidation reaction. Keywords: amino acids; bioorganic chemistry; carboxamidation reaction; chemically modified; DNA nucleosides; nucleic acids; Introduction For decades DNA has been known as the carrier of the genetic

• lysine derivatives onto nucleosides via a straightforward and easy domino carboxamidation reaction. Previously the groups of Gait and Eaton [41][42][43] have used this reaction to couple histamine or simple amine derivatives to both 5-iodo-2’-deoxyuridine and purine nucleosides. Although a large number

A simple copper-catalyzed two-step one-pot synthesis of indolo[1,2-a]quinazoline

• Chunpu Li,
• Lei Zhang,
• Shuangjie Shu and
• Hong Liu

Beilstein J. Org. Chem. 2014, 10, 2441–2447, doi:10.3762/bjoc.10.254

• aryl halides with active methylene compounds such as ethyl acetoacetate, malononitrile, cyanoacetate and their equivalents [8][9][10][11][12][13][14][15]. Copper-catalyzed domino reactions have also been used in the synthesis of nitrogen-containing compounds [16][17][18][19][20]. Ma et al reported a

• domino cyclization. Based on the previous work for the copper-catalyzed synthesis of 2-amino-1H-indole derivatives and copper-catalyzed N-arylation, we herein report a simple and efficient one-pot method to synthesize indolo[1,2-a]quinazolines by a sequential Ullmann-type C–C and C–N coupling. Compared

Chiral phosphines in nucleophilic organocatalysis

• Yumei Xiao,
• Zhanhu Sun,
• Hongchao Guo and
• Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

• excellent ee (up to 96%). In subsequent transformations, the β-lactone products underwent various ring opening reactions to provide very useful derivatives, such as 1,3-diketones and enol esters, with good diastereoselectivity. 2.12 Annulations through domino aza-MBH/Michael reactions Because

• organocatalytic asymmetric domino reactions allow the rapid construction of structurally complex molecules from readily available starting materials in two or more steps in a single operation, they have attracted much attention. Bifunctional chiral phosphines are ideal chiral catalysts for tandem reactions. In

• 2010, using the bifunctional chiral phosphine G1, bearing both Brønsted acid and Lewis base units, as the catalyst, asymmetric domino aza-MBH/aza-Michael reactions of activated alkenes and N-tosylimines with Michael acceptor moieties at their ortho positions were accomplished to give chiral 1,3

Multicomponent reactions in nucleoside chemistry

• Mariola Koszytkowska-Stawińska and
• Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

• considerable number of pacidamycin analogues. 4. The multicomponent domino reactions initiated by the Knoevenagel condensation The Knoevenagel condensation can be considered as one of the most useful tools for the formation of C=C double bonds. The condensation products, i.e., electron-deficient alkenes

• , readily act in subsequent reactions as Michael acceptors, Diels–Alder (hetero)dienes or dienophiles, or dipolarophiles. Multicomponent domino reactions initiated by the Knoevenagel condensation are a valuable tool for the construction of many compounds with complex molecular structures [90]. The syntheses

• shown in Scheme 23 and Scheme 24 represent examples of the Knoevenagel condensation-initiated domino reactions where the nucleoside aldehyde (i.e., 5-formyl-3',5'-di-O-acetyl-2'-deoxyuridine (14) or 5-formyl-2'-deoxyuridine (27)) acted as the Knoevenagel acceptor. Compounds 61 to 65 were prepared by the

The Ugi four-component reaction as a concise modular synthetic tool for photo-induced electron transfer donor-anthraquinone dyads

• Sarah Bay,
• Gamall Makhloufi,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 1006–1016, doi:10.3762/bjoc.10.100

• diversity-oriented syntheses of chromophores [62][63][64][65][66][67][68][69] we have established accesses to chromophores in a one-pot fashion based upon transition metal catalysis as an entry to consecutive multicomponent [70][71] and domino reactions [72]. The highly convergent synthetic approach by

Primary-tertiary diamine-catalyzed Michael addition of ketones to isatylidenemalononitrile derivatives

• Akshay Kumar and
• Swapandeep Singh Chimni

Beilstein J. Org. Chem. 2014, 10, 929–935, doi:10.3762/bjoc.10.91

• -component version of the reaction by a domino Knoevenagel–Michael sequence. The Michael adduct 4a was transformed into spirooxindole 6 by a reduction with sodium borohydride in a highly enantioselective manner. Keywords: 3,3'-disubstituted oxindoles; Michael reaction; organocatalysis; primary-tertiary

• component process involving a domino Knoevenagel–Michael sequence was developed. 3,3'-Disubstituted oxindole could be transformed into spirooxindoles by reduction with NaBH4. Oxindole based Michael acceptors. Primary-tertiary diamine organocatalysts. Diamine catalyzed Michael addition of acetone to

Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilyl)methyl)aniline with cyclic α,β-unsaturated carbonyl compounds

• Dominik Lenhart and
• Thorsten Bach

Beilstein J. Org. Chem. 2014, 10, 890–896, doi:10.3762/bjoc.10.86

• higher type selectivity. The domino process was suppressed and the plain addition product 22 was obtained in 75% yield (Scheme 7). The latter result suggested that the previously discussed (Scheme 3) addition reaction to 5,6-dihydro-2H-pyran-2-one (12) might also lead to a single product if performed

• 2 [38] and of N-methyl-N-((trimethylsilyl)methyl)aniline (5) to 2-cyclohexenone (6) [41]. Ir-catalyzed formation of tricyclic product 10 by a domino radical addition reaction to α,β-unsaturated lactone 9. Ir-catalyzed addition reactions of N-methyl-N-((trimethylsilyl)methyl)aniline (5) to 5,6

• -dihydro-2H-pyran-2-one (12). Ir-catalyzed addition reactions of N-methyl-N-((trimethylsilyl)methyl)aniline (5) to 2-cyclopentenone (15). Ir-catalyzed formation of tricyclic products 19 by a domino radical addition reaction to α,β-unsaturated lactams 18. Ir-catalyzed addition reactions of N-methyl-N

Domino reactions of 2H-azirines with acylketenes from furan-2,3-diones: Competition between the formation of ortho-fused and bridged heterocyclic systems

• Alexander F. Khlebnikov,
• Mikhail S. Novikov,
• Viktoriia V. Pakalnis,
• Roman O. Iakovenko and
• Dmitry S. Yufit

Beilstein J. Org. Chem. 2014, 10, 784–793, doi:10.3762/bjoc.10.74

• routes of bis[1,3]oxazino[3,2-a:3′,2′-d]pyrazine skeleton formation revealed a new domino reaction of 3-aryl-2H-azirines occurring in the presence of furandiones: acid-catalyzed dimerization to dihydropyrazine followed by consecutive cycloaddition of the latter to two molecules of acylketenes. Keywords

• : acylketene; azirine; domino reaction; furandione; Introduction 2H-Azirines, the most strained nitrogen unsaturated heterocyclic systems, are versatile building blocks for the construction of various heterocyclic nitrogen-containing compounds. Because 2H-azirines contain an activated C=N double bond and a

Phosphinate-containing heterocycles: A mini-review

• Olivier Berger and
• Jean-Luc Montchamp

Beilstein J. Org. Chem. 2014, 10, 732–740, doi:10.3762/bjoc.10.67

• synthesis of chiral bicyclic phosphinates 23a–k by domino hydrophosphinylation/Michael/Michael reaction was realized by Fourgeaud et al. (Scheme 10) [25]. Several 1-oxa-3-aza-6-phosphabicyclo[3.3.0]octanes derivatives 23a–k were obtained in yields around 70% by reacting allenes 21 with imines 22 derived

One-pot three-component synthesis and photophysical characteristics of novel triene merocyanines

• Christian Muschelknautz,
• Robin Visse,
• Jan Nordmann and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 599–612, doi:10.3762/bjoc.10.51

• , and photophysics. Inspired by the concept of a diversity-oriented synthetic approach to chromophores [19][20][21][22][23][24][25][26] we have launched a program to apply transition metal-catalyzed processes as an entry to consecutive multicomponent [27][28] and domino reactions [29]. These highly

• ][40] and pyranoindoles [41] via domino sequences. Interestingly, our versatile three-component enaminone synthesis [42][43] could be readily extended in a vinylogous fashion with enamines furnishing orange or deep red diene chromophores 2 and 3 that display aggregation induced emission [31]. In

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• particular molecules or were employed as a key step for the synthesis of more complex structures in domino approaches. For example, Che, Wong and co-workers successfully applied A3-coupling to aldehyde-containing oligosaccharides 8 [38]. The best catalyst for this reaction was 10 mol % of the [Au(C^N)Cl2

A catalyst-free multicomponent domino sequence for the diastereoselective synthesis of (E)-3-[2-arylcarbonyl-3-(arylamino)allyl]chromen-4-ones

• Pitchaimani Prasanna,
• Pethaiah Gunasekaran,
• Subbu Perumal and
• J. Carlos Menéndez

Beilstein J. Org. Chem. 2014, 10, 459–465, doi:10.3762/bjoc.10.43

• Madrid, Spain 10.3762/bjoc.10.43 Abstract The three-component domino reactions of (E)-3-(dimethylamino)-1-arylprop-2-en-1-ones, 3-formylchromone and anilines under catalyst-free conditions afforded a library of novel (E)-3-(2-arylcarbonyl-3-(arylamino)allyl)-4H-chromen-4-ones in good to excellent yields

• –Hilman condensation, and a final deoxygenation. The deoxygenation is assumed to be induced by carbon monoxide resulting from the thermal decomposition of the dimethylformamide solvent. Keywords: chromones; domino reactions; Michael additions; multicomponent reactions; transfer hydrogenation

• to structurally diverse carbocycles and heterocycles, an area in which we have recently become interested [33][34][35][36][37][38][39][40][41][42]. Thus, the present study ia a continuation of our research program on the construction of novel heterocycles employing one-pot green domino-multicomponent

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• overview of the new mechanistic insights concerning the title reaction is provided as well as a condensed account on the biological relevance of the topic. Heteroatom variants of this rearrangement are covered briefly. Keywords: cycloheptadiene; divinylcyclopropane rearrangement; domino reactions; natural

Four-component reaction of cyclic amines, 2-aminobenzothiazole, aromatic aldehydes and acetylenedicarboxylate

• Hong Gao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 2934–2939, doi:10.3762/bjoc.9.330

• : benzothiazole; domino reaction; electron-deficient alkyne; multicomponent reaction; pyrrolidinone; Introduction Over fifty years ago, Huisgen firstly described the addition reactions of nitrogen-containing heterocycles to electron-deficient alkynes to form 1,4-dipolar intermediates, which can reacted

• sequentially with other reagents to give cycloaddition products [1][2]. From then on much developments on the chemistry of Huisgen 1,4-dipoles have been achieved [3][4]. In the past few years, Huisgen 1,4-dipoles have been recognized as key components for designing practical multicomponent reactions and domino

• nitrogen-containing heterocycles [11][12][13][14][15][16]. In this hot research field, we also successfully developed a series of domino reactions containing primary amine, electron-deficient alkynes and the other components, and found several efficient synthetic protocols for versatile heterocycles and

Gold(I)-catalyzed domino cyclization for the synthesis of polyaromatic heterocycles

• Mathieu Morin,
• Patrick Levesque and
• Louis Barriault

Beilstein J. Org. Chem. 2013, 9, 2625–2628, doi:10.3762/bjoc.9.297

A combined continuous microflow photochemistry and asymmetric organocatalysis approach for the enantioselective synthesis of tetrahydroquinolines

• Erli Sugiono and
• Magnus Rueping

Beilstein J. Org. Chem. 2013, 9, 2457–2462, doi:10.3762/bjoc.9.284

• photocyclization–reduction cascade. Optimization of the Brønsted acid catalyzed transfer hydrogenation of quinolines.a Scope of the continuous-flow photocyclization–asymmetric reduction domino sequence.a

Flexible synthesis of anthracycline aglycone mimics via domino carbopalladation reactions

• Markus Leibeling and
• Daniel B. Werz

Beilstein J. Org. Chem. 2013, 9, 2194–2201, doi:10.3762/bjoc.9.258

• Markus Leibeling Daniel B. Werz Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany 10.3762/bjoc.9.258 Abstract A synthesis of anthracycline aglycone derivatives is described. The key step utilizes a powerful domino carbopalladation

• different products and a broad range of structural diversity. Keywords: anthracyclines; carbohydrates; carbopalladation; catalysis; domino reaction; natural products; Introduction Anthracyclines are a widespread class of natural products which belong to the group of aromatic polyketides [1]. Most of them

• motif in a few additional steps. Results and Discussion Retrosynthetic strategy After having established several methods of domino carbopalladation reactions which employ dialkynyl-substituted bromoglycals [17][18][19][20] or bromoarenes [21], we envisioned to apply a similar procedure for the

Post-Ugi gold-catalyzed diastereoselective domino cyclization for the synthesis of diversely substituted spiroindolines

• Amit Kumar,
• Dipak D. Vachhani,
• Sachin G. Modha,
• Sunil K. Sharma,
• Virinder S. Parmar and
• Erik V. Van der Eycken

Beilstein J. Org. Chem. 2013, 9, 2097–2102, doi:10.3762/bjoc.9.246

• adducts which are subjected to a cationic gold-catalyzed diastereoselective domino cyclization to furnish diversely substituted spiroindolines. All the reactions run via an exo-dig attack in the hydroarylation step followed by an intramolecular diastereoselective trapping of the imminium ion. The whole

• ][39][40][41][42][43]. We have recently reported a post-Ugi gold-catalyzed intramolecular domino cyclization sequence which produces spiroindolines (Scheme 1) [44]. The first step in this sequence is an Ugi four-component reaction (Ugi-4CR) [4][5] with 2-alkynoic acid as an alkyne source. The second

• materials. Based on this work and our continuous interest in transition metal catalysis [45][46][47][48][49][50][51][52][53][54], multicomponent reactions [55][56][57] and the chemistry of the indole core [58][59][60], we herein report a post-Ugi gold-catalyzed intramolecular domino cyclization sequence for

The chemistry of isoindole natural products

• Klaus Speck and
• Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

• induced domino epoxide-opening/rearrangement/cyclization cascade was accomplished by the group of Katoh (Scheme 22) [144]. The synthesis commenced with the conversion of dimethyl 2,6-dihydroxyterephthalate (172) to nitrile 173 within five consecutive steps. Hydrogenation and lactam formation of 173 gave

• diastereoisomers. The Lewis acid induced key step, a domino epoxide-opening/rearrangement/cyclization cascade, most likely proceeded in a stepwise manner via intermediate 179. Activation of the epoxide with boron trifluoride etherate induces the planned sigmatropic [1,2]-methyl and [1,2]-hydride shifts to generate

Gold catalysis for organic synthesis II

• F. Dean Toste

Beilstein J. Org. Chem. 2013, 9, 2040–2041, doi:10.3762/bjoc.9.241

• tandem or domino process that can be employed for the synthesis of complex polycyclic structures. These articles demonstrate the power of gold catalysis for the construction of complex structures, including the development of tandem processes, the expedient synthesis of heterocyclic structures, and

One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor

• Mark C. Bagley,
• Vincenzo Fusillo,
• Robert L. Jenkins,
• M. Caterina Lubinu and
• Christopher Mason

Beilstein J. Org. Chem. 2013, 9, 1957–1968, doi:10.3762/bjoc.9.232

• recent years there has been renewed interest in this transformation for its application in target synthesis [50], in the development of one-pot procedures for pyridine synthesis [50][51][52][53][54][55][56][57][58], and for incorporation into domino processes [57][58][59]. Given our precedent that

Preparation of optically active bicyclodihydrosiloles by a radical cascade reaction

• Koichiro Miyazaki,
• Yu Yamane,
• Ryuichiro Yo,
• Hidemitsu Uno and
• Akio Kamimura

Beilstein J. Org. Chem. 2013, 9, 1326–1332, doi:10.3762/bjoc.9.149

• treatment of chiral enyne compounds. A good trans-selectivity was observed in the reaction. Results and Discussion We examined the cascade process using optically active enyne precursor 1a, which was prepared by a Michael/aldol domino reaction to chiral sulfinimines followed by thermal elimination and N