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

• to produce intermediate C, with concomitant formation of a Cu(I) species. The brominated intermediate C undergoes a cross-coupling reaction with the alkynyl copper species to give the desired product 3. We have detected brominated intermediate C during the reaction. We have also examined the reaction

Synthesis of six-membered silacycles by borane-catalyzed double sila-Friedel–Crafts reaction

• Yafang Dong,
• Masahiko Sakai,
• Kazuto Fuji,
• Kohei Sekine and
• Yoichiro Kuninobu

Beilstein J. Org. Chem. 2020, 16, 409–414, doi:10.3762/bjoc.16.39

• , the transformation of the amino groups in phenoxasilin 3a into phenyl groups was carried out (Scheme 5). First, the ammonium salt 4 was prepared by treating 3a with MeOTf followed by a palladium-catalyzed cross-coupling reaction with the Grignard reagent (PhMgBr) that afforded the desired diphenylated

Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds

• Vuyisa Mzozoyana,
• Fanie R. van Heerden and
• Craig Grimmer

Beilstein J. Org. Chem. 2020, 16, 190–199, doi:10.3762/bjoc.16.22

• cross-coupling reaction [17], Negishi cross-coupling reaction [18] and Wittig reaction [17]. The concept of the incorporation of fluorine into organic molecules has gained much interest since Fried and Sabo reported the improvement of the therapeutic index of cortisol by the incorporation of a fluorine

Allylic cross-coupling using aromatic aldehydes as α-alkoxyalkyl anions

• Akihiro Yuasa,
• Kazunori Nagao and
• Hirohisa Ohmiya

Beilstein J. Org. Chem. 2020, 16, 185–189, doi:10.3762/bjoc.16.21

• homoallylic alcohol derivatives [12][13][14]. Results and Discussion Specifically, the three-component allylic cross-coupling reaction of benzaldehyde (1a, 0.4 mmol), tert-butyl cinnamyl carbonate (2a, 0.2 mmol) and (dimethylphenylsilyl)boronic acid pinacol ester [PhMe2SiB(pin)] (0.4 mmol) occurred in the

• )CuCl (53%) in terms of the chemical yield. Notably, the allylic cross-coupling reaction did not occur at all without Pd(OCOCF3)2–DPPF or (SIPr)CuCl, and thus the palladium and copper catalysts cooperatively acted in the allylic cross-coupling. Scheme 3 shows the substrate range of aromatic aldehydes 1

An improved, scalable synthesis of Notum inhibitor LP-922056 using 1-chloro-1,2-benziodoxol-3-one as a superior electrophilic chlorinating agent

• Nicky J. Willis,
• Elliott D. Bayle,
• George Papageorgiou,
• David Steadman,
• Benjamin N. Atkinson,
• William Mahy and
• Paul V. Fish

Beilstein J. Org. Chem. 2019, 15, 2790–2797, doi:10.3762/bjoc.15.271

• biology of Notum and build target validation to underpin new drug discovery programs. Results: An improved, scalable synthesis of 1 is reported. Key modifications include: (1) the introduction of the C7-cyclopropyl group was most effectively achieved with a Suzuki–Miyaura cross-coupling reaction with MIDA

• group was most effectively achieved with a Suzuki–Miyaura cross-coupling reaction with MIDA-boronate 11 (5 → 6); and (2) C6 chlorination was performed with 1-chloro-1,2-benziodoxol-3-one (12) (6 → 7) as a mild selective electrophilic chlorination agent. 4-Chlorothieno[3,2-d]pyrimidine (3) was either

• modifications include: (1) the introduction of the C7-cyclopropyl group was most effectively achieved with a Suzuki–Miyaura cross-coupling reaction with MIDA-boronate 11 (5 → 6); and (2) C6 chlorination was performed with 1-chloro-1,2-benziodoxol-3-one (12) (6 → 7) as a mild selective electrophilic chlorination

A chiral self-sorting photoresponsive coordination cage based on overcrowded alkenes

• Constantin Stuckhardt,
• Diederik Roke,
• Wojciech Danowski,
• Edwin Otten,
• Sander J. Wezenberg and
• Ben L. Feringa

Beilstein J. Org. Chem. 2019, 15, 2767–2773, doi:10.3762/bjoc.15.268

• formed revealing that a chiral self-sorting process takes place. In addition, two of the cage isomers can bind a tosylate anion in solution by formation of a host–guest complex. Results and Discussion Ligands Z-1 and E-1 (Scheme 1) were synthesized by a Suzuki cross-coupling reaction of 3

A new approach to silicon rhodamines by Suzuki–Miyaura coupling – scope and limitations

• Thines Kanagasundaram,
• Antje Timmermann,
• Carsten S. Kramer and
• Klaus Kopka

Beilstein J. Org. Chem. 2019, 15, 2569–2576, doi:10.3762/bjoc.15.250

• catalyst, different substituted boroxines were assessed to explore the scope of the Pd-catalyzed cross-coupling reaction. Conclusions: A number of silicon rhodamines were synthesized under the optimized conditions in up to 91% yield without the necessity of HPLC purification. Moreover, silicon rhodamines

• atom of 9b or sterical reasons (the chlorine in 2’-position might lead to repulsion during the cross-coupling reaction). The reaction of the triflate with cyano-substituted phenylboroxines 10b and 11b led to silicon rhodamine dyes 14 and 15 in poor yields of 23 and 19%, respectively. The reaction

• carbonate resulted in no reaction at all (Table 1, entry 5). Whereby usage of potassium phenyltrifluoroborate (19) resulted in a yield comparable to boroxine 18b (Table 1, entry 6), usage of pinacol ester 20 showed no reaction in the cross-coupling reaction (Table 1, entry 7). Although described

Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis

• Zhen Cao,
• Aline Lacoudre,
• Cybille Rossy and
• Brigitte Bibal

Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239

• reactions of alkynes. Results and Discussion Synthesis of silver(I) complexes Ligand 1 was synthesized in one step, from commercially available 9,10-dibromoanthracene and 2-(methylthio)phenylboronic acid, using a Suzuki–Miyaura cross-coupling reaction. Notably, the yield was low (26%) [55], and the X-ray

Functionalization of 4-bromobenzo[c][2,7]naphthyridine via regioselective direct ring metalation. A novel approach to analogues of pyridoacridine alkaloids

• Benedikt C. Melzer,
• Alois Plodek and
• Franz Bracher

Beilstein J. Org. Chem. 2019, 15, 2304–2310, doi:10.3762/bjoc.15.222

• ]. Reaction of allyl iodide (17) with metalated 9d after addition of catalytic amounts of CuCN∙2LiCl led to the formation of the 5-allyl compound 18 in 37% yield. Metalation of 9d using TMPMgCl∙LiCl and subsequent transmetalation with ZnCl2 followed by Negishi cross-coupling reaction in the presence of Pd(dba

Norbornadiene-functionalized triazatriangulenium and trioxatriangulenium platforms

• Roland Löw,
• Talina Rusch,
• Tobias Moje,
• Fynn Röhricht,
• Olaf M. Magnussen and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1815–1821, doi:10.3762/bjoc.15.175

• decomposition, which is a necessary precondition for ultra-high vacuum STM investigations. The 3-bromo-2-cyano-substituted norbornadiene 4 was synthesized as described in the literature (Scheme 1) [10][11][12]. 4 was converted to 5 with trimethylsilylacetylene (72%) in a Sonogashira cross-coupling reaction. The

• obtained in a convergent synthesis (Scheme 2). Boronic ester 9 was synthesized as described in the literature [15]. In a Suzuki cross-coupling reaction norbornadiene 4 was coupled with 9 to the extended norbornadiene 10 (38%), which was attached to the TATA platform 6 to yield the extended norbornadiene

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

Synthesis of 9-O-arylated berberines via copper-catalyzed C_Ar–O coupling reactions

• Qiaoqiao Teng,
• Xinhui Zhu,
• Qianqian Guo,
• Weihua Jiang,
• Jiang Liu and
• Qi Meng

Beilstein J. Org. Chem. 2019, 15, 1575–1580, doi:10.3762/bjoc.15.161

• leading to the failure of direct BBRB cross coupling. 9-O-Aryl berberine scope via cross-coupling reaction. 9-O-Ph-linked berberine dimer through double cross-coupling reaction. Optimization of the reaction conditions.a Supporting Information Supporting Information File 138: Experimental details and

Diazocine-functionalized TATA platforms

• Roland Löw,
• Talina Rusch,
• Fynn Röhricht,
• Olaf Magnussen and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1485–1490, doi:10.3762/bjoc.15.150

• a function of electronic coupling (conjugation) of the azo unit to gold. The para-diazocine-TATA 1 was synthesized in a 5-step synthesis route (Scheme 1). Bromotoluene 3 was synthesized as described [26]. In a Sonogashira cross-coupling reaction acetylene-substituted toluene 5 was prepared from

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• starting material, but also ring fusion to selenophene was achieved by Cu-catalyzed C–Se cross-coupling reaction [28]. The detailed geometric structure and the packing behaviour in the solid state of triacenes 2–4 have been elucidated by single crystal X-ray structure analysis and X-ray diffraction on

• reinvestigated the synthesis of DTT 1 by using a Cu-catalyzed C–S cross-coupling reaction with potassium sulfide (K2S) as sulfur source [29]. The best results for this C–S ring-closure reaction were achieved by reacting 3,3’-diiodo-2,2’-bithiophene (5) [30] with the system K2S and copper iodide (CuI) as catalyst

• deprotection with TBAF in 66% yield, with selenourea and copper oxide nanoparticles surprisingly did not lead to any targeted DSS 4 in the attempted C–Se cross-coupling reaction. The structures of the prepared novel selenolotriacenes 2–4 and known DTT 1 were characterized by means of NMR spectroscopy

Insertion of [1.1.1]propellane into aromatic disulfides

• Robin M. Bär,
• Gregor Heinrich,
• Martin Nieger,
• Olaf Fuhr and
• Stefan Bräse

Beilstein J. Org. Chem. 2019, 15, 1172–1180, doi:10.3762/bjoc.15.114

• opening of 1 with Grignard reagents enables the synthesis of aryl and some alkyl-substituted BCPs and a subsequent cross-coupling reaction [5][18]. To provide bicyclo[1.1.1]pentylamine as a building block in large-scale syntheses, Bunker et al. developed a synthesis of hydrazine BCP via a manganese

Solid-phase synthesis of biaryl bicyclic peptides containing a 3-aryltyrosine or a 4-arylphenylalanine moiety

• Iteng Ng-Choi,
• Àngel Oliveras,
• Lidia Feliu and
• Marta Planas

Beilstein J. Org. Chem. 2019, 15, 761–768, doi:10.3762/bjoc.15.72

• cross-coupling reaction [15][16][17][18][19] or via a Pd-catalyzed C–H activation reaction [20][21]. We have used the former reaction for the solid-phase preparation of biaryl cyclic peptides bearing a Phe-Phe, a Phe-Tyr or a Tyr-Tyr linkage [22][23]. Our approach involved the synthesis of the linear

Synthesis of C₃-symmetric star-shaped molecules containing α-amino acids and dipeptides via Negishi coupling as a key step

• Sambasivarao Kotha and
• Saidulu Todeti

Beilstein J. Org. Chem. 2019, 15, 371–377, doi:10.3762/bjoc.15.33

• containing unusual AAA units through cyclotrimerization and Negishi cross-coupling reaction as key steps under operationally simple reaction conditions. Here, we have used the readily available starting materials 4-iodoacetophenone (8) and L-serine (3). The C3-symmetric building blocks prepared were coupled

• , 2928, 1606, 1596, 1434, 783, 505 cm−1. Exemplar C3-symmetric peptide scaffolds reported in the literature. Preparation of compound 7 from L-serine (3). Preparation of the trimerized product 9. Synthesis of compound 11 via Negishi cross-coupling reaction. Synthesis of C3-symmetric trimers 12, 13 and 14

A novel and efficient synthesis of phenanthrene derivatives via palladium/norbornadiene-catalyzed domino one-pot reaction

• Yue Zhong,
• Wen-Yu Wu,
• Shao-Peng Yu,
• Tian-Yuan Fan,
• Hai-Tao Yu,
• Nian-Guang Li,
• Zhi-Hao Shi,
• Yu-Ping Tang and
• Jin-Ao Duan

Beilstein J. Org. Chem. 2019, 15, 291–298, doi:10.3762/bjoc.15.26

• and natural products. Results and Discussion We initiated our investigations by evaluating the three-component cross-coupling reaction of 2-iodotoluene (1a), ortho-bromobenzoyl chloride (2a) and norbornadiene, and we optimized the reaction conditions [21]. Firstly, the reaction took place under Pd

Molecular iodine-catalyzed one-pot multicomponent synthesis of 5-amino-4-(arylselanyl)-1H-pyrazoles

• Camila S. Pires,
• Daniela H. de Oliveira,
• Maria R. B. Pontel,
• Jean C. Kazmierczak,
• Roberta Cargnelutti,
• Diego Alves,
• Raquel G. Jacob and
• Ricardo F. Schumacher

Beilstein J. Org. Chem. 2018, 14, 2789–2798, doi:10.3762/bjoc.14.256

• methodologies describing the transition metal-catalyzed cross-coupling reaction of diorganyl diselenides with (hetero)aryl, alkenyl, and alkynyl halides or pseudo-halides [3], an updated protocol that describe reduced waste generation and atom-economy is desired. In this context, the multicomponent cyclization

Transition metal-free oxidative and deoxygenative C–H/C–Li cross-couplings of 2H-imidazole 1-oxides with carboranyl lithium as an efficient synthetic approach to azaheterocyclic carboranes

• Lidia A. Smyshliaeva,
• Mikhail V. Varaksin,
• Pavel A. Slepukhin,
• Oleg N. Chupakhin and
• Valery N. Charushin

Beilstein J. Org. Chem. 2018, 14, 2618–2626, doi:10.3762/bjoc.14.240

• cross-coupling reaction of 2,2-dimethyl-4-phenyl-2H-imidazole 1-oxide (1a) with carboranyllithium 2 was chosen as a model reaction. It has finally been found that the best yield of 4a is achieved using AcCl as a deoxygenative agent at room temperature with stirring of the resulted reaction mixture for

Synthesis of aryl sulfides via radical–radical cross coupling of electron-rich arenes using visible light photoredox catalysis

• Amrita Das,
• Mitasree Maity,
• Simon Malcherek,
• Burkhard König and
• Julia Rehbein

Beilstein J. Org. Chem. 2018, 14, 2520–2528, doi:10.3762/bjoc.14.228

• prefunctionalized sulfenylating reagents. Recently Lei and co-workers reported a DDQ-mediated selective radical–radical cross coupling between electron-rich arenes and thiols [40]. Miyake et al. reported the visible light-promoted cross-coupling reaction between aryl halides and arylthiols via an intermolecular

Synergistic approach to polycycles through Suzuki–Miyaura cross coupling and metathesis as key steps

• Sambasivarao Kotha,
• Milind Meshram and
• Chandravathi Chakkapalli

Beilstein J. Org. Chem. 2018, 14, 2468–2481, doi:10.3762/bjoc.14.223

• (SM) cross-coupling reaction is also considered as one of the most versatile methods for C–C bond formation [8][9][10][11][12]. Application of a wide range of organometallic reagents (e.g., organoboron reagents) are possible due to their commercial availability. Owing to the mild reaction conditions

Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine

• Piotr Pomarański,
• Piotr Roszkowski,
• Jan K. Maurin,
• Armand Budzianowski and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2018, 14, 2384–2393, doi:10.3762/bjoc.14.214

• atropselective Suzuki–Miyaura cross-coupling reaction on 3,4,5-tribromo-2,6-dimethylpyridine was studied. Results: Reactions with various amounts of ortho-substituted phenylboronic acids with 3,4,5-tribromo-2,6-dimethylpyridine gave a series of mono- di- and triarylpyridine derivatives which allowed to draw

• [10][11][12][13]. In recent years, many successful attempts to regioselective [14][15][16][17], chemoselective [18][19][20][21] or atropselective [1][22][23][24][25][26] synthesis of biaryls were presented, often taking advantage of the popular and useful Suzuki–Miyaura cross-coupling reaction

• chloropyridines, significantly less-reactive in palladium cross-coupling reaction, were used as substrates allowing the formation of the desired products. Another regioselective Suzuki–Miyaura cross-coupling reaction on 3’,5’-dibromopyridinium N-(2’-azinyl)aminides afforded a series of 3-aryl(or heteroaryl)-5

Practical tetrafluoroethylene fragment installation through a coupling reaction of (1,1,2,2-tetrafluorobut-3-en-1-yl)zinc bromide with various electrophiles

• Ken Tamamoto,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 2375–2383, doi:10.3762/bjoc.14.213

• oxycupration of tetrafluoroethylene (TFE) [18][19][20]. Gouverneur et al. disclosed a Cu(I)-mediated cross-coupling reaction using ArCF2CF2SiMe3 derivatives that produced the corresponding tetrafluoroethylenated compounds [21]. Beier’s group also described a broad range of tetrafluoroethylene compounds

• generated by the reductive coupling of in situ-formed RCF2CF2MgCl·LiCl with various electrophiles [22][23]. Our group revealed that commercially available 4-bromo-3,3,4,4-tetrafluorobut-1-ene (1) underwent a Cu(0)-mediated cross-coupling reaction with aromatic iodides in DMSO at 160 °C in a sealed-tube

• presence of 10 mol % of CuI in DMF at 50 °C for 24 h resulted in limited formation (11% yield) of the cross-coupling product 4a (Table 2, entry 1). The Cu(I)-catalyzed cross-coupling reaction with 3a was proposed to take place via the following three key reaction steps [36]: (i) transmetallation from 2-Zn

Stereoselective total synthesis and structural revision of the diacetylenic diol natural products strongylodiols H and I

• Pamarthi Gangadhar,
• Sayini Ramakrishna,
• Ponneri Venkateswarlu and
• Pabbaraja Srihari

Beilstein J. Org. Chem. 2018, 14, 2313–2320, doi:10.3762/bjoc.14.206

• to long chain aliphatic aldehydes in the presence of N-methylephedrine [17] or an amino alcohol–zinc complex [18] and the Cadiot–Chodkiewicz cross-coupling reaction as key steps [14][15][16]. In continuation to our research interest on the synthesis of acetylenic compounds [19][20][21], recently we

• lithium(trimethylsilyl)acetylide to get the coupled product 24. The latter compound on further treatment with K2CO3 in MeOH [26] furnished the desilylated propargylic alcohol 19 (Scheme 2). The copper(I)-catalyzed Cadiot–Chodkiewicz [27] cross-coupling reaction between bromoalkyne 18 [28] and terminal