Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• , Nara 630-0192, Japan Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan 10.3762/bjoc.20.30 Abstract The “precursor approach” has proved particularly valuable for the preparation of insoluble and unstable π-conjugated polycyclic compounds (π-CPCs), which cannot be

• ultimate elimination of chalcogen fragments upon thermal activation, photoirradiation and electron exchange. Keywords: arenes; chalcogens; extrusion; fused-ring systems; precursor approach; Introduction π-Conjugated polycyclic compounds (π-CPCs), including polycyclic aromatic hydrocarbons and their

• -conjugated polycyclic compounds appeared as particularly valuable in this field. Indeed, many of them demonstrated excellent performances as active components of electronic devices such as organic field effect transistors (OFETs), organic photovoltaic cells (OPVs) and organic light-emitting diodes (OLEDs

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

• the Ph3P−I• species III, forming the cationic intermediate F. Finally, deprotonation of intermediate F yielded the product 34g. Functional polycyclic compounds, such as indene-containing polycyclic motifs and N-containing polyheterocycles are commonly found in many natural products and pharmaceuticals

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• . This reaction provided efficient synthetic protocols for the synthesis of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] derivatives. A plausible reaction mechanism was proposed to explain the selective formation of the different polycyclic compounds

Synthesis of substituted 8H-benzo[h]pyrano[2,3-f]quinazolin-8-ones via photochemical 6π-electrocyclization of pyrimidines containing an allomaltol fragment

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky,
• Mikhail E. Minyaev and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2023, 19, 778–788, doi:10.3762/bjoc.19.58

• derivative 11a. Thus, all our attempts towards the regiospecific photochemical conversion of pyrimidines 10 into polycyclic compounds 12 were unsuccessful. A plausible mechanism for the considered phototransformation of compounds 9 and 10 is depicted in Scheme 6. At first, pyrimidines 10 undergo a 6π

• the simultaneous formation of the products 11a–f. At the same time, we failed to increase the yield of the polycyclic products 12 by additional conversion of the byproducts 11a–f. At this point, we assumed that the conversion of the analogous hydroxy derivatives 11g–j into the polycyclic compounds 12

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• this review can serve to guide and to inspire future advances in synthetic organic chemistry for this kind of polycyclic compounds. Examples of anthracene derivatives and their applications. Rhodium-catalyzed oxidative coupling reactions of arylboronic acids with internal alkynes. Rhodium-catalyzed

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

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

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• of fluorine-containing compounds The utility of the Pauson–Khand reaction in the preparation of polycyclic compounds bearing both nitrogenated and cyclopentenone rings, two ubiquitous domains in drugs and natural products, has been reported in various contributions using 1,n-enynes, particularly 4

Preparation of 2-phospholene oxides by the isomerization of 3-phospholene oxides

• Péter Bagi,
• Réka Herbay,
• Nikolett Péczka,
• Zoltán Mucsi,
• István Timári and
• György Keglevich

Beilstein J. Org. Chem. 2020, 16, 818–832, doi:10.3762/bjoc.16.75

• -coupled transformations [18][22][23]. Polycyclic compounds incorporating a P-heterocyclic moiety are of special importance due to their optoelectronic properties and applications [24][25][26]. Moreover, a few biologically active 5-membered P-heterocyclic derivatives are also known, which showed promising

Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

• ). Subsequent Diels–Alder cycloaddition reactions with dienophiles and further aromatization reactions paved the way for a convenient access to structurally diverse polycyclic compounds. For instance, installing the C-aryl and spiro-C-aryl glycosides in the same moiety was successfully achieved. An application

An overview of the cycloaddition chemistry of fulvenes and emerging applications

• Ellen Swan,
• Kirsten Platts and
• Anton Blencowe

Beilstein J. Org. Chem. 2019, 15, 2113–2132, doi:10.3762/bjoc.15.209

• can be further influenced by substituents, making them useful building blocks for the synthesis of polycyclic compounds [32][35][36][37][38][39]. This is another rich and interesting area of chemistry, although further discussion of heterofulvenes is outside the scope of the current overview and the

Synthesis of spirocyclic scaffolds using hypervalent iodine reagents

• Fateh V. Singh,
• Priyanka B. Kole,
• Saeesh R. Mangaonkar and
• Samata E. Shetgaonkar

Beilstein J. Org. Chem. 2018, 14, 1778–1805, doi:10.3762/bjoc.14.152

• functionalized benzocoumarins to spirocyclic lactones. In 2015, Du and co-workers [74] reported a spirocyclization of diarylacetylenes to fused spiro polycyclic compounds through a hypervalent iodine-mediated cascade annulation reaction. In this reaction, the Lewis acid BF3·Et2O acts as catalyst which activates

Recent applications of ring-rearrangement metathesis in organic synthesis

• Sambasivarao Kotha,
• Milind Meshram,
• Priti Khedkar,
• Shaibal Banerjee and
• Deepak Deodhar

Beilstein J. Org. Chem. 2015, 11, 1833–1864, doi:10.3762/bjoc.11.199

• 139 and 140. Further, NMR spectroscopic studies showed the presence of products 139 and 140 as a mixture of isomers, and it was difficult to purify this mixture by conventional separation techniques (Scheme 29). Recently, Kotha and Gunta have reported a RRM to generate various polycyclic compounds

• carbocycles by employing the RRM protocol starting with appropriate norbornene derivatives [43]. Recently, Kotha and Ravikumar [44] have found a new route to various polycyclic compounds by employing the DA reaction and the RRM protocol as key steps. To this end, the key building block 202 has been prepared

• various Ru–carbene complexes in one-pot sequence generate various complex targets. It is an atom economic process producing a wide range of polycyclic compounds containing highly demanding structures efficiently. Starting with relatively simple substrates, the final compounds obtained by the RRM process

Design and synthesis of fused polycycles via Diels–Alder reaction and ring-rearrangement metathesis as key steps

• Sambasivarao Kotha and
• Ongolu Ravikumar

Beilstein J. Org. Chem. 2015, 11, 1259–1264, doi:10.3762/bjoc.11.140

• are well suited. Here, we demonstrate that an endocyclic bis-norbornene system undergoes an RRM with a suitably placed olefin moiety to generate complex polycyclic compounds. RRM of norbornene derivatives are common, however, reports dealing with RRM of bis-norbornene derivatives are rare [21][22

• reaction and RRM as key steps. Here, we generated polycyclic compounds with 10 stereocenters involving six fused rings in four steps starting with readily available starting materials such as 1,3-cyclopentadiene, 1,3-cyclohexadiene and 1,4-benzoquinone. Further studies to expand the scope of this strategy

A new and convenient synthetic way to 2-substituted thieno[2,3-b]indoles

• Roman A. Irgashev,
• Arseny A. Karmatsky,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2015, 11, 1000–1007, doi:10.3762/bjoc.11.112

• thieno[3,2-b]pyrrole ring systems have been incorporated in the structures of various fused polycyclic compounds (heteroacenes), which have been used as efficient hole-transport materials for organic light emitting diodes (OLEDs) or field effect transistors (OFETs) [9][10][11][12][13][14][15]. Taking

Further exploration of the heterocyclic diversity accessible from the allylation chemistry of indigo

• Alireza Shakoori,
• John B. Bremner,
• Mohammed K. Abdel-Hamid,
• Anthony C. Willis,
• Rachada Haritakun and
• Paul A. Keller

Beilstein J. Org. Chem. 2015, 11, 481–492, doi:10.3762/bjoc.11.54

• synthesis of novel polycyclic compounds. Further, we report for the first time the synthesis of derivatives of these heterocycles, including those using the sterically hindered allyl reagents with terminal methyl substituents. The allylation reaction also provides access to new hydroxylated heterocyclic

Design and synthesis of novel bis-annulated caged polycycles via ring-closing metathesis: pushpakenediol

• Sambasivarao Kotha and
• Mirtunjay Kumar Dipak

Beilstein J. Org. Chem. 2014, 10, 2664–2670, doi:10.3762/bjoc.10.280

• addition; pentacycloundecane (PCUD); ring-closing metathesis; Introduction Caged polycyclic compounds draw the attention of synthetic organic chemists due to their unusual reactivity patterns as well as their strained nature [1][2][3][4][5][6][7][8][9]. Several pentacycloundecane (PCUD) related molecules

Photochemical approach to functionalized benzobicyclo[3.2.1]octene structures via fused oxazoline derivatives from 4- and 5-(o-vinylstyryl)oxazoles

• Ivana Šagud,
• Simona Božić,
• Željko Marinić and
• Marija Šindler-Kulyk

Beilstein J. Org. Chem. 2014, 10, 2222–2229, doi:10.3762/bjoc.10.230

• ] and sydnones [11][12][13], as routes to polycyclic compounds, we turned our attention to oxazole derivatives. The oxazole structure is commonly found in natural products and pharmaceuticals [14][15][16][17] and is applied in useful reagents and intermediates in organic synthesis [18][19][20][21][22

• spectra in C6D6 of rel-(9S)-12a (a) and rel-(9S)-11 (b). Synthesis of 4- (1) and 5-(2-vinylstyryl)oxazoles (2). Irradiation of 4- (1) and 5-(2-vinylstyryl)oxazoles (2) (crude reaction mixtures). Plausible mechanisms of oxazoline ring-opening in photoproduct 10. Mechanism of the formation of polycyclic

• compounds (8–10). Reactions of the photochemical product 8 with EtOH, MeOD and H2O/silica gel. Plausible mechanisms of oxazoline ring opening in photoproduct 10 and formation of 12. Supporting Information Supporting Information File 560: Experimental part, NMR and IR spectra. Acknowledgements This work

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Photochemical and thermal intramolecular 1,3-dipolar cycloaddition reactions of new o-stilbene-methylene-3-sydnones and their synthesis

• Kristina Butković,
• Željko Marinić,
• Krešimir Molčanov,
• Biserka Kojić-Prodić and
• Marija Šindler-Kulyk

Beilstein J. Org. Chem. 2011, 7, 1663–1670, doi:10.3762/bjoc.7.196

• such a system, where two chromophores, stilbene and sydnone, are divided by a methylene bridge, an intramolecular 1,3-dipolar cycloaddition and the formation of diverse polycyclic compounds could be expected. Herein we describe, for the first time, the synthesis of cis- and trans-3-(stilbenylmethyl

• cis or trans double bond of stilbene moiety, affording polycyclic compounds 11 and 12, respectively. The same starting compounds also react thermally: The sydnone moiety in 3a reacts as a masked azomethine dipole with trans configuration on the stilbene moiety by intramolecular [3 + 2] cycloaddition

Tribenzotriquinacenes bearing three peripheral or bridgehead urea groups stretched into the 3-D space

• Jörg Tellenbröker and
• Dietmar Kuck

Beilstein J. Org. Chem. 2011, 7, 329–337, doi:10.3762/bjoc.7.43

• bridgeheads of the rigid, convex–concave, C3v-symmetrical molecular framework are reported. 1H NMR data point to supramolecular aggregation of these TBTQ derivatives in low-polarity solvents. Keywords: convex–concave structures; polycyclic compounds; supramolecular chemistry; tribenzotriquinacenes; urea

Enantioselective synthesis of tricyclic amino acid derivatives based on a rigid 4-azatricyclo[5.2.1.0^2,6]decane skeleton

• Matthias Breuning,
• Tobias Häuser,
• Christian Mehler,
• Christian Däschlein,
• Carsten Strohmann,
• Andreas Oechsner and
• Holger Braunschweig

Beilstein J. Org. Chem. 2009, 5, No. 81, doi:10.3762/bjoc.5.81

• β-turn-inducing building blocks in peptidomimetics and for chiral auxiliaries in asymmetric organocatalysis. Keywords: amino acid; enantioselective synthesis; norbornane; polycyclic compounds; pyrrolidine; Introduction Unnatural amino acids with a rigid bowl-shaped backbone have received

Synthesis and Diels–Alder cycloaddition reaction of norbornadiene and benzonorbornadiene dimers

• Bilal Nişancı,
• Erdin Dalkılıç,
• Murat Güney and
• Arif Daştan

Beilstein J. Org. Chem. 2009, 5, No. 39, doi:10.3762/bjoc.5.39

• orientation) also confirms the exo structures for 11, 12, 18 and 19 (Figure 1). In summary, the synthesis and cycloaddition reaction of norbornadiene and benzonorbornadiene dimers was investigated and new norbornanoid polycyclic compounds, which open up several synthetic and mechanical investigations, were

New modification of the Perkow reaction: halocarboxylate anions as leaving groups in 3-acyloxyquinoline- 2,4(1H,3H)-dione compounds

• Oldřich Paleta,
• Karel Pomeisl,
• Stanislav Kafka,
• Antonín Klásek and
• Vladislav Kubelka

Beilstein J. Org. Chem. 2005, 1, No. 17, doi:10.1186/1860-5397-1-17

• , amides or acyl halides. [5][6] Examples of the successful Perkow reaction also include chlorofluoro ketones, e.g. 1,3-dichloro-1,1,3,3-tetrafluoroacetone,[7] α-halonitroalkanes, and in rare cases also polycyclic compounds[8] such as 3,3-dichloro-1-methylquinoline-2,4(1H,3H)-dione. [9] In the Perkow