An efficient synthesis of the guaiane sesquiterpene (−)-isoguaiene by domino metathesis

• Yuzhou Wang,
• Ahmed F. Darweesh,
• Patrick Zimdars and
• Peter Metz

Beilstein J. Org. Chem. 2019, 15, 858–862, doi:10.3762/bjoc.15.83

• subjected to dibromoolefination with ylide 19 as described for the transformation of aldehyde 18. Use of the preformed ylide 19 led to reproducibly higher yields of 24 in comparison with the application of tetrabromomethane and triphenylphosphine [23]. One-pot alkyne formation and methylation [23] of 24 to

Strong hyperconjugative interactions limit solvent and substituent influence on conformational equilibrium: the case of cis-2-halocyclohexylamines

• Camila B. Francisco,
• Cleverton S. Fernandes,
• Ulisses Z. de Melo,
• Roberto Rittner,
• Gisele F. Gauze and
• Ernani A. Basso

Beilstein J. Org. Chem. 2019, 15, 818–829, doi:10.3762/bjoc.15.79

• -Fluorocyclohexanol was prepared according the literature [36] to provide cis-2-fluorocyclohexylamine. cis-2-Fluorocyclohexylamine (F) was obtained by a Mitsunobu–Gabriel reaction, as described by Thvedt and co-workers [37]. Under nitrogen atmosphere, trans-2-fluorocyclohexanol (6.00 mmol), triphenylphosphine (6.60

Homo- and hetero-difunctionalized β-cyclodextrins: Short direct synthesis in gram scale and analysis of regiochemistry

• Gábor Benkovics,
• Mihály Bálint,
• Éva Fenyvesi,
• Erzsébet Varga,
• Szabolcs Béni,
• Konstantina Yannakopoulou and
• Milo Malanga

Beilstein J. Org. Chem. 2019, 15, 710–720, doi:10.3762/bjoc.15.66

• ditosylation reactions and for the observed partial regioselectivity in reaction 2 (Scheme 2). Additionally, a Vilsmeier–Haack/Appel-type iodination reaction was performed with β-CD, using triphenylphosphine (PPh3) and iodine (I2) in DMF (reaction 3, Scheme 2). This reaction is known to be selective for the

• area percentage ratio 52:48, respectively (reaction 3, Scheme 2). This outcome might be attributed to the bulkiness of the halogenating agent (triphenylphosphine–iodine adduct) and to the mild reaction conditions used (i.e., a relatively low temperature for the iodination), under which the substitution

Synthesis of 2H-furo[2,3-c]pyrazole ring systems through silver(I) ion-mediated ring-closure reaction

• Vaida Milišiūnaitė,
• Rūta Paulavičiūtė,
• Eglė Arbačiauskienė,
• Vytas Martynaitis,
• Wolfgang Holzer and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2019, 15, 679–684, doi:10.3762/bjoc.15.62

• AgOTf efficiently catalyzed the intramolecular cyclization of phenoxyethynyl diols into 2,3-unsaturated lactones [38]. In our case, the addition of 10 mol % chloro(triphenylphosphine)gold(I) improved the yield of product 4a to 69% (Table 1, entry 4). However the best results were obtained when AgOTf was

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

• with aryl iodide (0.30 mmol, 1.0 equiv), ortho-bromobenzoyl chlorides (0.36 mmol, 1.2 equiv), norbornadiene (0.60 mmol, 2.0 equiv), Pd(OAc)2 (5 mol %), triphenylphosphine (12.5 mol %), Cs2CO3 (0.675 mmol, 2.25 equiv), and DMF (4 mL). The mixture was stirred at 105 °C under nitrogen atmosphere for 10 h

Mechanistic studies of an L-proline-catalyzed pyridazine formation involving a Diels–Alder reaction with inverse electron demand

• Anne Schnell,
• J. Alexander Willms,
• S. Nozinovic and
• Marianne Engeser

Beilstein J. Org. Chem. 2019, 15, 30–43, doi:10.3762/bjoc.15.3

• and the organic layer was washed six times with a 2:1 mixture of deionized water/methanol (6 × 40 mL). The aqueous layer was evaporated to yield 17 mg of a light pink solid. The 1H NMR, 31P NMR and ESIMS spectra show an impurity of triphenylphosphine oxide in the product, which does not interfere with

• ), 130.4 or 130.3 (C-15), 129.4 (C-3), 128.7 (C-10), 128.6 (C-11), 128.1 (C-4), 128.1 (C-9), 128.1, 118.3 (C-2), 117.6 (C-2), 31.0 or 30.6 (C-1). Signals not allocated to 4∙Br: 132.9, 132.7, 132.3, 132.2, 132.1, 131.7, 131.7, 131.6; 31P{1H} NMR (162 MHz, CDCl3, 298 K) δ [ppm] 29.22 (triphenylphosphine

The activity of indenylidene derivatives in olefin metathesis catalysts

• Maria Voccia,
• Steven P. Nolan,
• Luigi Cavallo and
• Albert Poater

Beilstein J. Org. Chem. 2018, 14, 2956–2963, doi:10.3762/bjoc.14.275

• (1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene) and the IMes (1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) NHC ligands. The group trans to the NHC ligand is triphenylphosphine for all catalysts. Table 1 includes the energy profiles for the substituted indenylidenes, bearing methyl

Nucleoside macrocycles formed by intramolecular click reaction: efficient cyclization of pyrimidine nucleosides decorated with 5'-azido residues and 5-octadiynyl side chains

• Jiang Liu,
• Peter Leonard,
• Sebastian L. Müller,
• Constantin Daniliuc and
• Frank Seela

Beilstein J. Org. Chem. 2018, 14, 2404–2410, doi:10.3762/bjoc.14.217

• ’-azido-2’,5’-dideoxycytidine 2. Earlier, the nucleoside precursor 1 was used for DNA cross-linking and labelling [36]. The unprotected nucleoside 1 was treated with equimolar amounts of carbon tetrabromide and triphenylphosphine and a five-fold excess of sodium azide to obtain the azide derivative 2 (37

β-Hydroxy sulfides and their syntheses

• Mokgethwa B. Marakalala,
• Edwin M. Mmutlane and
• Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143

• organophosphine was found to have a profound effect on the catalytic activity; some reactions were sluggish when tricyclohexylphosphine or triphenylphosphine were used as catalysts. The tributylphosphine acts as a nucleophilic trigger to attack, and thus initiates the reaction. 3.1.1.3 Use of zinc salts. In

Anomeric modification of carbohydrates using the Mitsunobu reaction

• Julia Hain,
• Patrick Rollin,
• Werner Klaffke and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138

• reagents, mostly triphenylphosphine and a dialkyl azodicarboxylate. This reaction has been frequently used in carbohydrate chemistry for the modification of sugar hydroxy groups. Modification at the anomeric position, leading mainly to anomeric esters or glycosides, is of particular importance in the

• triphenylphosphine [1]. This reaction has ever since become known as the “Mitsunobu reaction”, being a frequently utilized tool in organic synthesis. In 1981, Mitsunobu published a first review about this reaction, entitled "The Use of Diethyl Azodicarboxylate and Triphenylphosphine in Synthesis and Transformation

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

• Jiang has very recently described a complementary method for the synthesis of carbazoles by combining cyclic diaryl-λ3-iodanes with sodium azide in the presence of copper(I) thiophene-2-carboxylate (CuTc) and triphenylphosphine. The reaction affords the expected of N–H free derivatives 63 in moderate to

Preparation, structure, and reactivity of bicyclic benziodazole: a new hypervalent iodine heterocycle

• Akira Yoshimura,
• Michael T. Shea,
• Cody L. Makitalo,
• Melissa E. Jarvi,
• Gregory T. Rohde,
• Akio Saito,
• Mekhman S. Yusubov and
• Viktor V. Zhdankin

Beilstein J. Org. Chem. 2018, 14, 1016–1020, doi:10.3762/bjoc.14.87

• have investigated the analogous oxidatively assisted coupling reaction of carboxylic acids 9 with alcohols 10 or amine 12 using benziodazole 7a under similar conditions (Scheme 3). The reaction of butyric acid (9a) with benzyl alcohol (10a) using benziodiazole 7a in the presence of triphenylphosphine

Electrochemically modified Corey–Fuchs reaction for the synthesis of arylalkynes. The case of 2-(2,2-dibromovinyl)naphthalene

• Fabiana Pandolfi,
• Isabella Chiarotto and
• Marta Feroci

Beilstein J. Org. Chem. 2018, 14, 891–899, doi:10.3762/bjoc.14.76

• homologation to terminal alkynes can also be obtained using the Corey–Fuchs reaction [11]. This is a two-step reaction in which an aldehyde is at first converted into a 1,1-dibromoalkene with chain extension by one carbon atom through the reaction with carbon tetrabromide and triphenylphosphine (Scheme 1

Liquid-assisted grinding and ion pairing regulates percentage conversion and diastereoselectivity of the Wittig reaction under mechanochemical conditions

• Kendra Leahy Denlinger,
• Lianna Ortiz-Trankina,
• Preston Carr,
• Kingsley Benson,
• Daniel C. Waddell and
• James Mack

Beilstein J. Org. Chem. 2018, 14, 688–696, doi:10.3762/bjoc.14.57

• . Results and Discussion Liquid-assisted grinding To focus the study, benzaldehyde, benzyl bromide, polymer-supported triphenylphosphine (PS-C6H4-PPh2) and potassium carbonate were ball-milled in a stainless steel vial with two LAG solvents at opposite ends of the dielectric spectrum, as well as a control

• stilbene and the least amount of benzyl benzoate, we began our study on the yield and diastereoselectivity using this solvent. First, we were interested in the influence of ethanol on the mechanochemical reaction of the alkyl halide and the polymer-supported triphenylphosphine. For this purpose, PS-C6H4

• coefficient under mechanochemical conditions are ongoing. Experimental NMR spectra were obtained using a Bruker Avance 400 MHz spectrometer. Deuterated chloroform was obtained from Cambridge Isotope Laboratories Inc., Addover, MA, and used without further purification. Triphenylphosphine-functionalized

Synthesis and stability of strongly acidic benzamide derivatives

• Frederik Diness,
• Niels J. Bjerrum and
• Mikael Begtrup

Beilstein J. Org. Chem. 2018, 14, 523–530, doi:10.3762/bjoc.14.38

• ; found, 434.0006. 4'-Methoxy-N-((trifluoromethyl)sulfonyl)-[1,1'-biphenyl]-4-carboxamide (15): Palladium(II) acetate (6 mg, 27 μmol), triphenylphosphine (20 mg, 76 μmol) and H2O (0.5 μL, 28 μmol) were mixed in degassed dimethylacetamide (1.0 mL). The catalyst was preformed by heating the mixture in a

Preparation of trinucleotide phosphoramidites as synthons for the synthesis of gene libraries

• Ruth Suchsland,
• Bettina Appel and
• Sabine Müller

Beilstein J. Org. Chem. 2018, 14, 397–406, doi:10.3762/bjoc.14.28

• -azidomethylbenzoyl)-protected nucelosides, followed by removal of the 5'-O-DMTr group and extension of the dimer to the trimer by coupling of another N-acyl-3'-O-(o-chlorophenylphosphate)nucleoside. The final removal of the 2-azidomethylbenzoyl group occurred by reduction of the azide with triphenylphosphine in

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

• Thanh-Tuân Bui,
• Fabrice Goubard,
• Malika Ibrahim-Ouali,
• Didier Gigmes and
• Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• -trifluoromethylated analogues in the presence of trimethylphosphine, with moderate to excellent yields (Scheme 33). The higher nucleophilicity of trimethylphosphine versus triphenylphosphine and the water solubility of trimethylphosphine oxide byproducts were essential elements in choosing the reducing agent. Both

• triphenylphosphine in acetonitrile at 60 °C [44]. The addition of catalytic amounts of sodium iodide, while not being essential for the production of the trifluoromethylsulfenylated substrates, permitted to slightly increase the yields (Scheme 35). For that matter, excellent yields were achieved indifferently of the

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• published the same reaction under slightly different conditions [46]. They used a combination CF3SO2Na/TBHP in the presence of catalytic amounts of copper chloride and triphenylphosphine. Trisubstituted alkenes (R3 and R4 ≠ H) were employed as substrates and diastereoisomers were obtained. The tert-butoxyl

Vinylphosphonium and 2-aminovinylphosphonium salts – preparation and applications in organic synthesis

• Anna Kuźnik,
• Roman Mazurkiewicz and
• Beata Fryczkowska

Beilstein J. Org. Chem. 2017, 13, 2710–2738, doi:10.3762/bjoc.13.269

• Wehman (Scheme 4) [10]. Vinylphosphonium salts can also be prepared by alkylation of phosphines (usually triphenylphosphine) with allyl halide derivatives and isomerization of allylphosphonium salts 4 thus obtained under the influence of bases such as triethylamine or sodium carbonate (Scheme 5) [11][12

• ][13]. Vinyl halides are relatively less reactive alkylating agents. However, the use of readily available vinyl triflates 5 for the alkylation of triphenylphosphine in THF solution in the presence of a catalytic amount of (Ph3P)4Pd (1–3 mol %) gave the expected vinylphosphonium salts in a yield of 62

• triphenylphosphine with 1-bromoethylbenzene. The resulting phosphonium salt 11 was then deprotonated to the corresponding ylide 12, which in the last step was subjected to bromination to give the expected α-bromoethylphosphonium bromide 13 [10]. 1.3. Peterson olefination of α-trimethylsilylphosphonium ylides with

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• with triphenylphosphine functionalized either by two or three phosphonic acid sodium salts; the former being more water soluble than the later [24]. This behavior is associated to the fact that the trisphosphonic acid sodium salt was already solvated at the solid state. The high polarity of the

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• Reaction Pecharsky and co-workers reported the solvent-free mechanochemical synthesis of phosphonium salts [54] and phosphorus ylides [55] in the presence of the weak base K2CO3. Mechanochemically prepared phosphorous ylide from triphenylphosphine in presence of K2CO3 was utilized for a one-pot solvent

Pd(OAc)₂/Ph₃P-catalyzed dimerization of isoprene and synthesis of monoterpenic heterocycles

• Dominik Kellner,
• Maximilian Weger,
• Andrea Gini and
• Olga García Mancheño

Beilstein J. Org. Chem. 2017, 13, 1807–1815, doi:10.3762/bjoc.13.175

• procedure towards the tail-to-tail dimer using readily available Pd(OAc)2 and inexpensive triphenylphosphine as ligand. Furthermore, simple screw cap vials are employed, allowing carrying out the reaction at low pressure. In addition, the potential of the dimer as a chemical platform for the preparation of

• been developed. A high selectivity towards the tail-to-tail dimer was achieved by using readily available Pd(OAc)2 and inexpensive triphenylphosphine as ligand in the presence of catalytic amounts of Et3N as base. The reaction can be performed with common chemicals and solvents at low pressure in

1-Imidoalkylphosphonium salts with modulated C_α–P⁺ bond strength: synthesis and application as new active α-imidoalkylating agents

• Jakub Adamek,
• Roman Mazurkiewicz,
• Anna Węgrzyk and
• Karol Erfurt

Beilstein J. Org. Chem. 2017, 13, 1446–1455, doi:10.3762/bjoc.13.142

• succinimide-derived products 5 (A = (CH2)2) were generally lower. In the case of N-(1-methoxyethyl)-1,8-naphthalimide the triphenylphosphine attack on the α-carbon resulted in the splitting of the Cα–N bond instead of the Cα–OMe bond and the corresponding 1-methoxyethyltriphenylphosphonium tetrafluoroborate

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

• A. Michael Downey and
• Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123