C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• much cheaper than diphenyl(2-(triethoxysilyl)ethyl)phosphine. With this setup, the flow system consisted of two mixtures: a mixture A containing furfural (0.7 M) and 2-(piperidin-1-yl)ethane-1,2-diamine (0.7 M) and a mixture B containing vinyltriethoxysilane (1.05 or 2.1 M) and the ruthenium catalyst

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• can be highly beneficial. Therefore, Skowerski and co-workers constructed a tube-in-tube reactor for the ring-closing metathesis of dienes 62 and 63 to macrocycles 65 or 66, respectively, mediated by ruthenium catalyst 64 (Scheme 15) [53]. The substrate and the catalyst are mixed in a Q-piece and

• ]. Solutions of dialkene 67 and the Z-selective ruthenium catalyst 68 in 1,2-dichloroethane are mixed and pumped through a tube-in-tube reactor continuously removing the ethylene formed in the ring-closing metathesis. At 70 °C and with a residence time of 3 h, civetone (69) is formed in 44% isolated yield with

Recent advances and perspectives in ruthenium-catalyzed cyanation reactions

• Thaipparambil Aneeja,
• Cheriya Mukkolakkal Abdulla Afsina,
• Padinjare Veetil Saranya and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 37–52, doi:10.3762/bjoc.18.4

• an efficient tool for the synthesis of organic compounds. Jain et al. put forward an oxidative cyanation of tertiary amines using an immobilized heterogeneous ruthenium catalyst (Figure 1) [39]. The optimized conditions comprised sodium cyanide (NaCN) (1.2 mmol) in acetic acid as cyanide source

• single-step. The proposed mechanism is depicted in Scheme 26. Xiao and co-workers developed an environmentally benign strategy for the oxidative cyanation of differently substituted alcohols using a manganese oxide nanorod-supported ruthenium catalyst (Scheme 27) [49]. They also evaluated the efficiency

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

• unsaturated oximes 130 using a combination of t-BuONO and a ruthenium catalyst (Scheme 43) [132]. The authors proposed that the interaction of unsaturated oxime with TBN produced a hydroxyiminomethylisoxazoline (Scheme 40) [130] that was transformed into the cyano-substituted oxazoline in the presence of a

• ruthenium catalyst. This possible reaction pathway was confirmed by a control experiment in which the hydroxyiminomethylisoxazoline was transformed to a nitrile in the presence of [RuCl2(p-cymene)]2. Aromatic oximes with various substituents, as well as heteroaromatic oximes, give cyano-substituted

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

• stereoisomeric diyne precursors was performed first by a ring-closing alkyne metathesis in the presence of Schrock’s molybdenum catalyst. Next, the diene units were installed by intermolecular enyne metathesis of the preformed cyclic alkyne with ethylene using Grubbs second-generation ruthenium catalyst (Scheme

• metathesis steps applying the second-generation Hoveyda–Grubbs Ru catalyst, while, unexpectedly, the second-generation Grubbs ruthenium catalyst was less active and gave rise to some side-products. (−)-Galanthamine An important alkaloid active in the treatment of mild to moderate Alzheimer's disease and

Efficient synthesis of 3,6,13,16-tetrasubstituted-tetrabenzo[a,d,j,m]coronenes by selective C–H/C–O arylations of anthraquinone derivatives

• Seiya Terai,
• Yuki Sato,
• Takuya Kochi and
• Fumitoshi Kakiuchi

Beilstein J. Org. Chem. 2020, 16, 544–550, doi:10.3762/bjoc.16.51

• tetrabenzo[a,d,j,m]coronene product indicated its self-assembling behavior in CDCl3. Keywords: C–H arylation; C–O arylation; oxidative cyclization; polycyclic aromatic hydrocarbons; ruthenium catalyst; Introduction Polycyclic aromatic hydrocarbons (PAHs) and their derivatives have attracted much attention

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

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• (Scheme 7). In more detail, the synthesis included ROMP of NB octyl ester or NB by means of metal coordination using the obtained telechelic polymers methyl triglycol ester in the presence of the bimetallic ruthenium catalyst followed by the addition of an excess of either a Pd-containing chain terminator

Ruthenium-based olefin metathesis catalysts with monodentate unsymmetrical NHC ligands

• Veronica Paradiso,
• Chiara Costabile and
• Fabia Grisi

Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292

• beneficial effect on the catalytic activity was observed. Indeed complex 22 revealed a very poor olefin metathesis catalyst, likely as a consequence of the excessive steric hindrance of the adamantyl moiety at the ruthenium center. It is worth to underline that the first Z-selective ruthenium catalyst (23

• at the backbone positions of the NHC framework has represented a remarkable advancement in the design of ruthenium olefin metathesis catalysts, due to the significant effects exerted on complexes' stability, reactivity and selectivity [51]. The first example of C1-symmetric ruthenium catalyst bearing

Cross metathesis-mediated synthesis of hydroxamic acid derivatives

• Shital Kumar Chattopadhyay,
• Subhankar Ghosh and
• Suman Sil

Beilstein J. Org. Chem. 2018, 14, 3070–3075, doi:10.3762/bjoc.14.285

• ruthenium catalyst has recently found applications [28][29][30]. However, similar attempts in our case, i.e., direct conversion of 4 + 5 → 7 proved to be problematic and conversion to the desired product was not observed under the attempted conditions. An intractable mixture of compounds was the result

The influence of the cationic carbenes on the initiation kinetics of ruthenium-based metathesis catalysts; a DFT study

• Magdalena Jawiczuk,
• Angelika Janaszkiewicz and
• Bartosz Trzaskowski

Beilstein J. Org. Chem. 2018, 14, 2872–2880, doi:10.3762/bjoc.14.266

• higher stabilities of dimers on solution (see Supporting Information File 1). First generation Grubbs and M1 indenylidene catalyst In the next step of the study we performed a computational investigation of possible pathways of the initiation of cationic ruthenium catalyst based on the commonly used 1st

Synthesis of a tyrosinase inhibitor by consecutive ethenolysis and cross-metathesis of crude cashew nutshell liquid

• Jacqueline Pollini,
• Valentina Bragoni and
• Lukas J. Gooßen

Beilstein J. Org. Chem. 2018, 14, 2737–2744, doi:10.3762/bjoc.14.252

• , undergoes smooth ethenolysis only in dichloromethane as the solvent (Scheme 3). Using more sustainable solvents or no solvent at all, the reaction gave almost no turnover, regardless of the ruthenium catalyst employed. However, as a 1.1 M solution in dichloromethane, the unsaturated components of CNSL were

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

•  25). Although the regioselectivity of the reaction was overall excellent for heteroarenes, it proved to be less satisfying for substituted arenes. Further investigations allowed the authors to propose a detailed mechanism, represented in Scheme 25. After excitation of the ruthenium catalyst through

Is the tungsten(IV) complex (NEt₄)₂[WO(mnt)₂] a functional analogue of acetylene hydratase?

• Matthias Schreyer and
• Lukas Hintermann

Beilstein J. Org. Chem. 2017, 13, 2332–2339, doi:10.3762/bjoc.13.230

• alkyne hydration catalyst (cf. Table 1) [24]. The catalyst solution was prepared in aqueous triethyleneglycol dimethyl ether (triglyme), because acetonitrile is a competitive inhibitor of the ruthenium catalyst [24], and acetone would have disturbed the DNPH-test for acetaldehyde. Bubbling acetylene

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• Ackermann group used another ruthenium catalyst, [RuCl2(p-cymene)]2 and developed a hydroxylation protocol for carbamates [77]. The hydroxylation occurred in DCE in the presence of PhI(OTFA)2 (Scheme 47). In intermolecular competition experiments, among amide, carbamate and ester, amide showed the highest

Synthesis of polyhydroxylated decalins via two consecutive one-pot reactions: 1,4-addition/aldol reaction followed by RCM/syn-dihydroxylation

• Michał Malik and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2016, 12, 2602–2608, doi:10.3762/bjoc.12.255

• ruthenium catalyst in the subsequent syn-dihydroxylation. As a result, the polyhydroxylated decalin derivative 12 was obtained. The syn-dihydroxylation of cyclic alkenes is among the most widely used methods for the introduction of hydroxy groups onto the ring. Such transformations are usually conducted

Synthesis and properties of fluorescent 4′-azulenyl-functionalized 2,2′:6′,2″-terpyridines

• Adrian E. Ion,
• Liliana Cristian,
• Mariana Voicescu,
• Masroor Bangesh,
• Augustin M. Madalan,
• Daniela Bala,
• Constantin Mihailciuc and
• Simona Nica

Beilstein J. Org. Chem. 2016, 12, 1812–1825, doi:10.3762/bjoc.12.171

• development of an efficient ruthenium catalyst for selective oxidation of both aliphatic and aromatic amines to nitriles [22]. The catalytic effectiveness of this ruthenium terpyridine complex was ascribed to the polarization effect of the azulene moiety attached at the terpyridine unit and it was sustained

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

• Barry M. Trost,
• Michael C. Ryan and
• Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

• [41] (Figure 1a). The proposed mechanism of this fascinating reaction involves chloride abstraction of the ruthenium catalyst by indium(III) triflate and phosphine ligand dissociation. The propargyl alcohol then coordinates to the now coordinatively unsaturated cyclopentadienylruthenium (CpRu

• was observed in THF, no such effect was seen in acetone. We postulate that there are two different enantiodetermining steps that center around a chosen solvent’s ability to epimerize a metal center following redox isomerization. (a) Mechanism for the redox biscycloisomerization reaction. (b) Ruthenium

• catalyst containing a tethered chiral sulfoxide. (c) Possible diastereomeric complexes formed from alcohol coordination. Failed sulfinate ester syntheses. Failed bicycloisomerization substrates. Reactions performed at 40 °C for 16 hours with 3 mol % of catalyst 1 in acetone at a 0.25 M concentration

A cross-metathesis approach to novel pantothenamide derivatives

• Jinming Guan,
• Matthew Hachey,
• Lekha Puri,
• Vanessa Howieson,
• Kevin J. Saliba and
• Karine Auclair

Beilstein J. Org. Chem. 2016, 12, 963–968, doi:10.3762/bjoc.12.95

• -methoxybenzaldehyde acetal protecting group in 9 is believed to tie back the alcohols and prevent them from coordinating and deactivating the ruthenium catalyst. When testing the scope of the metathesis reaction with 9, a variety of partners were chosen, including not only acrylic acid (10a), but also 2-vinylpyridine

New metathesis catalyst bearing chromanyl moieties at the N-heterocyclic carbene ligand

• Agnieszka Hryniewicka,
• Szymon Suchodolski,
• Agnieszka Wojtkielewicz,
• Jacek W. Morzycki and
• Stanisław Witkowski

Beilstein J. Org. Chem. 2015, 11, 2795–2804, doi:10.3762/bjoc.11.300

• of organic chemistry since 1992, when Grubbs discovered the first well-defined ruthenium catalyst [2]. Nearly 400 ruthenium heterocyclic carbene-coordinated olefin metathesis catalysts were prepared until 2010 [3]. Since 2011, when Grubbs reported the synthesis of a Z-selective catalyst [4], several

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• ruthenium catalyst induced polymerization of the bicyclic monomer 22 to homopolymer 23, followed by polymerization of the additional comonomer 20 at the Ru site of 23 to yield the copolymer 24 (Scheme 10). Based on their potential application as tools for biological detection and signal amplification

Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics

• Kevin Lafaye,
• Cyril Bosset,
• Lionel Nicolas,
• Amandine Guérinot and
• Janine Cossy

Beilstein J. Org. Chem. 2015, 11, 2223–2241, doi:10.3762/bjoc.11.241

• deactivation caused by amino derivatives will be first presented and discussed. RCM and CM involving alkenes possessing N-heteroaromatics will be then successively examined [38]. Review Mechanistic insights into amine-induced catalyst deactivation Recently, intensive studies dealing with ruthenium catalyst

• was first treated with HCl to form the corresponding hydrochloride salt which was then reacted with the ruthenium catalyst 36 under diluted conditions to deliver 35. After reduction of the double bond, the targeted (R)-(+)-muscopyridine was isolated (Scheme 14). A similar strategy was used in the

• synthesis of the tris-pyrrole macrocyclic pigment nonylprodigiosin [52]. A preliminary protonation of the tris-pyrrole followed by a RCM applied to 37 in the presence of the ruthenium catalyst 36 gave the macrocycle 38, which was then transformed into the saturated derivative 39 using the Wilkinson’s

Latent ruthenium–indenylidene catalysts bearing a N-heterocyclic carbene and a bidentate picolinate ligand

• Thibault E. Schmid,
• Florian Modicom,
• Adrien Dumas,
• Etienne Borré,
• Loic Toupet,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2015, 11, 1541–1546, doi:10.3762/bjoc.11.169

• residues are known to induce ruthenium-complex decomposition, and increase purification complexity [25]. Moreover, in a previous report regarding the synthesis of a dormant ruthenium catalyst bearing a chelating carboxylate ligand, spontaneous chloride/carboxylate exchange with elimination of HCl has been

Design and synthesis of hybrid cyclophanes containing thiophene and indole units via Grignard reaction, Fischer indolization and ring-closing metathesis as key steps

• Sambasivarao Kotha,
• Ajay Kumar Chinnam and
• Mukesh E. Shirbhate

Beilstein J. Org. Chem. 2015, 11, 1514–1519, doi:10.3762/bjoc.11.165

• of the starting material leading to a complex mixture of products as indicated by thin-layer chromatography (TLC). It is known that sulfur can coordinate with the ruthenium catalyst and deactivate the catalytic cycle [35][36][37]. Therefore, the diolefin did not undergo the RCM sequence. Next, we