Ammonium-tagged ruthenium-based catalysts for olefin metathesis in aqueous media under ultrasound and microwave irradiation

• Łukasz Gułajski,
• Andrzej Tracz,
• Katarzyna Urbaniak,
• Stefan J. Czarnocki,
• Michał Bieniek and
• Tomasz K. Olszewski

Beilstein J. Org. Chem. 2019, 15, 160–166, doi:10.3762/bjoc.15.16

• , the cross metathesis (CM) between alcohol 8 and the electron-deficient cross partner methyl acrylate (10, Table 1). All reactions were run at 36 °C in D2O promoted either by microwave (µW) or ultrasound (US) irradiation, and for comparison purposes also with standard magnetic stirring. In the case of

• is in agreement with the known fact that in protic solvents ruthenium hydrides are formed leading to isomerisation byproducts [66]. Finally, we were pleased to see that the use of ultrasound or microwave irradiation were beneficial for the CM of alcohol 8 with methyl acrylate (10, Table 1, entries 5

Ring-opening metathesis of some strained bicyclic systems; stereocontrolled access to diolefinated saturated heterocycles with multiple stereogenic centers

• Zsanett Benke,
• Melinda Nonn,
• Márton Kardos,
• Santos Fustero and
• Loránd Kiss

Beilstein J. Org. Chem. 2018, 14, 2698–2707, doi:10.3762/bjoc.14.247

• model compound was first subjected to CM with methyl acrylate. When the reaction was performed in the presence of Ru-based catalysts, in CH2Cl2, either at reflux temperature or at 20 °C, it gave a mixture of monometathesised products ((±)-21 and (±)-22) after 6 h together with a large amount of

• derivative (80 mg) in anhydrous CH2Cl2 (15 mL), catalyst (5 mol %, see Table) and methyl vinyl ketone or methyl acrylate (4 equiv) were added and the mixture was stirred for the time and temperature indicated in text. After completion of the reaction (monitored by TLC), the mixture was concentrated under

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

• ) compared to the conventional method that generally takes days to a week for completion. The reaction of methyl acrylate with different para-substituted aryl aldehydes in the presence of 20 mol % 1,4-diazabicyclo[2.2.2]octane (DABCO) catalyst at 0.5–45 h yielded the MBH products in 28–98% yield [53]. Wittig

Synthesis of benzothiophene and indole derivatives through metal-free propargyl–allene rearrangement and allyl migration

• Jinzhong Yao,
• Yajie Xie,
• Lianpeng Zhang,
• Yujin Li and
• Hongwei Zhou

Beilstein J. Org. Chem. 2017, 13, 1866–1870, doi:10.3762/bjoc.13.181

• products in good yields (2a–k). A variety of substituents, such as p-COOEt, p-COCH3, dichloro, p-NO2, p-CF3 and p-CN were well-tolerated during the reaction, leading to 2a–f in 54–83% yield. The presence of methyl acrylate or pyridine was also well-tolerated, as exemplified in the formation of 2g,h in 48

Iodination of carbohydrate-derived 1,2-oxazines to enantiopure 5-iodo-3,6-dihydro-2H-1,2-oxazines and subsequent palladium-catalyzed cross-coupling reactions

• Michal Medvecký,
• Igor Linder,
• Luise Schefzig,
• Hans-Ulrich Reissig and
• Reinhold Zimmer

Beilstein J. Org. Chem. 2016, 12, 2898–2905, doi:10.3762/bjoc.12.289

• lithium chloride [35] leading to the expected coupling products syn-13 and syn-14 in 39% and 82% yield, respectively (Scheme 5). In both cases, only the E-configured 2-substituted alkyl acrylates were isolated. The moderate yield in the Heck reaction with methyl acrylate 12a is very likely caused by the

Experimental and theoretical insights in the alkene–arene intramolecular π-stacking interaction

• Valeria Corne,
• Ariel M. Sarotti,
• Carmen Ramirez de Arellano,
• Rolando A. Spanevello and
• Alejandra G. Suárez

Beilstein J. Org. Chem. 2016, 12, 1616–1623, doi:10.3762/bjoc.12.158

• slightly stronger interaction for 6a (see Supporting Information File 1 for further details). To shed light on these issues, we next computed the interaction energies for the complexes of methyl acrylate (7) and 4-trifluoromethylanisole (8), 4-methoxyanisole (9) or anisole (10), (Scheme 2). For the

• (in kcal/mol) computed for 6d and 6b (in grey). X-ray thermal ellipsoid plot of 6a (50% probability level) showing the labeling scheme (hydrogen and carbon labels have been omitted for clarity). Synthesis of acrylates 6a,b. Complexes between methyl acrylate (7) and representative anisole derivatives

Rh-Catalyzed reductive Mannich-type reaction and its application towards the synthesis of (±)-ezetimibe

• Motoyuki Isoda,
• Kazuyuki Sato,
• Yurika Kunugi,
• Satsuki Tokonishi,
• Atsushi Tarui,
• Masaaki Omote,
• Hideki Minami and
• Akira Ando

Beilstein J. Org. Chem. 2016, 12, 1608–1615, doi:10.3762/bjoc.12.157

• phosphorus pentoxide directly before use, respectively. All imines were prepared from corresponding aldehydes and amines. Methyl acrylate was distilled directly before use. Other commercially available reagents were used without further purification. All experiments were carried out under an argon atmosphere

Development of chiral metal amides as highly reactive catalysts for asymmetric [3 + 2] cycloadditions

• Yasuhiro Yamashita,
• Susumu Yoshimoto,
• Mark J. Dutton and
• Shū Kobayashi

Beilstein J. Org. Chem. 2016, 12, 1447–1452, doi:10.3762/bjoc.12.140

• in high yield with high diastereo- and enantioselectivities. The reaction with methyl acrylate also proceeded in high yield with high enantioselectivity; however, in this case the exo/endo selectivity was moderate. Methyl vinyl ketone and methyl methacrylate reacted with 1a to afford the desired [3

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

• Takashi Nishikata,
• Alexander R. Abela,
• Shenlin Huang and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

• product was obtained exclusively. Under optimized conditions, various acrylates and amides can be synthesized via C–H activation reactions (Figure 6). Methyl acrylate, which did not show good general reactivity with arylureas under previous conditions, could be coupled in excellent yields (5i, 5j, 5k). As

Asymmetric α-amination of 3-substituted oxindoles using chiral bifunctional phosphine catalysts

• Qiao-Wen Jin,
• Zhuo Chai,
• You-Ming Huang,
• Gang Zou and
• Gang Zhao

Beilstein J. Org. Chem. 2016, 12, 725–731, doi:10.3762/bjoc.12.72

• base to participate in the catalytic cycle. In 2015, we reported a novel asymmetric dual-reagent catalysis strategy based on these chiral phosphine catalysts [42], in which the zwitterion in situ generated from the chiral phosphine and methyl acrylate acted as an efficient catalyst for the asymmetric

• Mannich-type reaction. As an extension of this work, we then wondered if other electrophilic partners instead of methyl acrylate could be used to generate similar catalytically active species in situ. Also inspired by the Mitsunobu reaction [43], we reported herein the reaction of azodicarboxylates with 3

Self-assemblies of γ-CDs with pentablock copolymers PMA-PPO-PEO-PPO-PMA and endcapping via atom transfer radical polymerization of 2-methacryloyloxyethyl phosphorylcholine

• Jing Lin,
• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2015, 11, 2267–2277, doi:10.3762/bjoc.11.247

• a channel-like crystal structure. With an increase in the amount of γ-CDs added, they began to accommodate the poly(methyl acrylate) (PMA) segments dissociated from the core of the micelles. When more γ-CDs were threaded and slipped over the segments, the γ-CDs were randomly distributed along the

• compared with PPO or PMAA), respectively, these unmatched PRs possess the potential to be applied as dynamic-responsive materials, carriers for controlled drug release, biosensors and catalysts. Poly(methyl acrylate) (PMA) prepared via ATRP of methyl acrylate (MA) is a typical hydrophobic polymer with a

• Group Co., Ltd., China. The average molecular weight (Mn) is 4580 g/mol. Methyl acrylate (MA) was purchased from J&K Company, China, and was used after removal of inhibitors. Both 2-bromoisobutyryl bromide (BIBB) and N,N,N’,N”,N”-pentamethyldiethylenetriamine (PMDETA) were available from Sigma-Aldrich

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

• ring [78]. When olefin 93, bearing a pyridine without any substituent at C2 or C6, was treated with methyl acrylate in the presence of G-HII catalyst no reaction took place and the starting material was fully recovered. By contrast, the presence of a chlorine substituent at C2 on the pyridyl ring

• ). Various substituents on the pyridyl ring such as halides, trifluoromethyl or triflate groups were found to be suitable basicity modulators and the alkenes containing the corresponding disubstituted pyridines were efficiently coupled to methyl acrylate by utilizing a CM reaction. In addition, steric

Ru complexes of Hoveyda–Grubbs type immobilized on lamellar zeolites: activity in olefin metathesis reactions

• Hynek Balcar,
• Naděžda Žilková,
• Martin Kubů,
• Michal Mazur,
• Zdeněk Bastl and
• Jiří Čejka

Beilstein J. Org. Chem. 2015, 11, 2087–2096, doi:10.3762/bjoc.11.225

• of 1,7-octadiene and (−)-β-citronellene; HGIIN+Cl− on SBA-15 (HGIIN+Cl−/SBA-15) was the most active (TON up to 16000 in RCM of citronellene). HGIIN+Cl−/SBA-15 proved its versatility in RCM, enyne metathesis, metathesis of methyl oleate, and cross-metathesis of electron deficient methyl acrylate with

Cross metathesis of unsaturated epoxides for the synthesis of polyfunctional building blocks

• Meriem K. Abderrezak,
• Kristýna Šichová,
• Nancy Dominguez-Boblett,
• Antoine Dupé,
• Zahia Kabouche,
• Christian Bruneau and
• Cédric Fischmeister

Beilstein J. Org. Chem. 2015, 11, 1876–1880, doi:10.3762/bjoc.11.201

• Chemistry, Hlavova 2030, CZ-128 40 Prague, Czech Republic Faculty of Chemistry, University of Seville, E-41012 Seville, Spain 10.3762/bjoc.11.201 Abstract The cross metathesis of 1,2-epoxy-5-hexene (1) with methyl acrylate and acrylonitrile was investigated as an entry to the synthesis of polyfunctional

• cross metathesis of 1 with methyl acrylate was transformed by means of nucleophilic ring-opening of the epoxide to furnish a diol, an alkoxy alcohol and an amino alcohol in high yields. Keywords: cross metathesis; epoxide; ruthenium catalysts; tandem reactions; Introduction Catalytic carbon–carbon

• involving the cross metathesis of a commercially available epoxide-containing olefin with methyl acrylate and acrylonitrile and their subsequent transformations leading to multifunctional building blocks are reported. Results and Discussion Cross metathesis reactions involving electron-deficient olefins are

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

• system 234 (91%). Alternatively, a ROM–RCM–CM sequence was employed under similar reaction conditions in the presence of methyl acrylate (232) as a CM partner. The tandem metathesis product 233 was obtained in 68% yield along with the ROM–RCM product 234 in 18% yield (Scheme 47). Later, 7-azanorbornene

Nitro-Grela-type complexes containing iodides – robust and selective catalysts for olefin metathesis under challenging conditions

• Andrzej Tracz,
• Mateusz Matczak,
• Katarzyna Urbaniak and
• Krzysztof Skowerski

Beilstein J. Org. Chem. 2015, 11, 1823–1832, doi:10.3762/bjoc.11.198

• worse than nG-SIPr. As outlined in Table 2, all tested catalysts were similarly effective in CM of methyl undecenoate 12 with cis-1,4-diacetoxy-2-butene (13), but parent dichloro complexes provided smaller quantities of dimerization product of 12. In CM of 12 with electron deficient methyl acrylate 15

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

Matsuda–Heck reaction with arenediazonium tosylates in water

• Ksenia V. Kutonova,
• Marina E. Trusova,
• Andrey V. Stankevich,
• Pavel S. Postnikov and
• Victor D. Filimonov

Beilstein J. Org. Chem. 2015, 11, 358–362, doi:10.3762/bjoc.11.41

• conditions. Methyl acrylate (1a) was chosen as a model substrate as it is highly reactive in standard Matsuda–Heck reactions. Therefore, a solution of 4-nitrobenzenediazonium tosylate (2a) in water was allowed to react with 1.2 equiv of methyl acrylate (1a) in the presence of 1 mol % Pd(OAc)2 at rt, at 75 °C

• (t, 2H), 3.75 (t, 2H), 2.11 (m, 2H); 13C NMR (75 MHz, DMSO-d6) δ 165.6, 142.6, 138.5, 132.7, 129.0, 121.4, 118.5, 112.3, 61.3, 41.8, 31.1; HRMS m/z: calcd. for C13H12NO2Cl, 249.0551; found, 249.0548. Arylation of methyl acrylate (1a) with arenediazonium tosylate 2a. Arylation of alkenes with ADT

• . Arylation of methyl acrylate (1a) with arenediazonium tosylate 2a. Study of reaction conditions. Arylation of alkenes with arenediazonium tosylates in water under microwave heating. Supporting Information Supporting Information File 354: Additional experimental data. Acknowledgements This research was

Copper-catalyzed cascade reactions of α,β-unsaturated esters with keto esters

• Zhengning Li,
• Chongnian Wang and
• Zengchang Li

Beilstein J. Org. Chem. 2015, 11, 213–218, doi:10.3762/bjoc.11.23

• two chiral centers, and that produced a mixture of diastereomers with potential challenges in the stereoselectivities. Reaction of methyl acrylate (1d) with 2a and PMHS in toluene at 25 °C gave two diastereomers which were detected by GC, however inseparable by column chromatography. Formation of the

• hydride-catalyzed reductive aldolization of acetophenone [19]. Therefore, tert-butyl acrylate (1d) was used to replace methyl acrylate, and several biphosphorous ligands were screened for improving the diastereoselectivity (Table 3). Diastereomers of 3da were separated, which were subjected to further

• diastereomers were then deduced by 1H NMR chemical shifts of CHCH3 or OCH3. As shown in Table 3, syn-3da was favored when tert-butyl acrylate was used to replace the methyl acrylate (Table 3, entry 8 vs Table 2, entry 1). Higher yields were obtained in the presence of biphosphorous ligands (Table 3, entries 2–8

Morita–Baylis–Hillman reaction of acrylamide with isatin derivatives

• Radhey M. Singh,
• Kishor Chandra Bharadwaj and
• Dharmendra Kumar Tiwari

Beilstein J. Org. Chem. 2014, 10, 2975–2980, doi:10.3762/bjoc.10.315

• complicated TLC results. A change of substrate (N-benzyl-protected isatin), catalyst (DMAP) or other solvents (THF, DCM, dioxane), gave no different result. However, remarkably, when the activated alkene was changed from acrylamide to methyl acrylate, formation of required aza-MBH product 5aa in high purity

• access to these adducts for the rapid development of other methodologies. Optimization of the conditions and parameters revealed DABCO as a superior catalyst (Table 2). The reduction in the loading of methyl acrylate and catalyst, or dilution of the solutions did not have any major effect on time or

• yield. Thus, DABCO (0.25 equiv) along with methyl acrylate (3 equiv) in acetonitrile as a solvent was identified as the best condition (Table 2, entry 9). Next, the reaction on different substrates was further explored. The protocol was found to work consistently, delivering the product with a short

Relay cross metathesis reactions of vinylphosphonates

• Raj K. Malla,
• Jeremy N. Ridenour and
• Christopher D. Spilling

Beilstein J. Org. Chem. 2014, 10, 1933–1941, doi:10.3762/bjoc.10.201

• substituted vinylphosphonates 12a or 12b in good yield. In contrast, when vinylphosphonate 12a was subjected to a cross metathesis reaction with methyl acrylate, the cross metathesis product 16a was formed in low yield (~11%) as part of a complex mixture. More highly substituted vinylphosphonates (5 and 19

• ) failed to react at all with methyl acrylate under similar conditions, even with higher catalyst loading and extended reaction times. Initially, the synthesis of the allyl vinylphosphonate esters was achieved using a transesterification reaction catalysed by tetra n-butylammonium iodide (TBAI) (Scheme 5

• - and diallyl vinylphosphonates 21a and 21b. The products were isolated by silica gel chromatography to give 27% yield of the mono-allyl and 36% yield of the diallyl phosphonate esters. With the mono- and diallyl vinylphosphonates in hand, the cross metathesis reactions with methyl acrylate (a type II

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• impact on polymer solubility, including the presence of amine-functional groups and allyl polymers with a –CH2-spacer between the polymer backbone and the side chain or group [85][91]. These have since been used more as a set of guidelines as opposed to a set of hard-and-fast rules; poly(methyl acrylate

C–H-Functionalization logic guides the synthesis of a carbacyclopamine analog

• Sebastian Rabe,
• Johann Moschner,
• Marina Bantzi,
• Philipp Heretsch and
• Athanassios Giannis

Beilstein J. Org. Chem. 2014, 10, 1564–1569, doi:10.3762/bjoc.10.161

• inexpensive dehydroepiandrosterone (5) by the means of a copper-mediated C–H hydroxylation in the 12-position and a palladium-catalyzed coupling of methyl acrylate to an activated enol ether in the 17-position. In synthetic direction (Scheme 2), dehydroepiandrosterone (5) was protected as its

• -dimethylaminopyridine, pyridine, 25 °C; then KOAc, MeOH, 64 °C, 85% yield for the two steps) to give 8. Generation of an enol triflate from the carbonyl group in 8 (potassium hexamethyldisilazide, phenyl bis-triflimide, THF, −20 → −10 °C, 85% yield) set stage for a Heck-reaction with methyl acrylate (cat. Pd(OAc)2, cat

Olefin cross metathesis based de novo synthesis of a partially protected L-amicetose and a fully protected L-cinerulose derivative

• Bernd Schmidt and
• Sylvia Hauke

Beilstein J. Org. Chem. 2014, 10, 1023–1031, doi:10.3762/bjoc.10.102

• L-amicetal 4 [36]. Alternatively, we have used 2 as a substrate for a cross metathesis reaction with methyl acrylate under isomerization-free conditions to furnish enoate 5, which underwent cyclization to the lactone 6 after hydrogenation. Reduction of 6 with DIBAL-H eventually yields a protected L

• -amicetose 7 [35]. To avoid the last step of the sequence, we envisaged a cross metathesis with acroleine, rather than methyl acrylate, to give enal 8 which should undergo spontaneous lactol formation after hydrogenation and desilylation. However, compared to cross metathesis reactions with methyl acrylate

N-Alkylated dinitrones from isosorbide as cross-linkers for unsaturated bio-based polyesters

• Oliver Goerz and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 902–909, doi:10.3762/bjoc.10.88

• unsaturated polyester was cross-linked by a 1,3-dipolar cycloaddition with the received dinitrones 10a/b. The 1,3-dipolar cycloaddition led to a strong change of the mechanical properties which were investigated by rheological measurements. Nitrones derived from methyl acrylate (3a) and methyl crotonate (3b

• study the course of this cycloaddition the two low molecular model nitrones methyl 3-[benzylidene(oxido)amino]propanoate (3a) and methyl 3-[benzylidene(oxido)amino]butanoate (3b), were prepared from methyl acrylate (2a) and methyl crotonate (2b) with E-benzaldoxime (1) (Scheme 1), respectively. The

• . 1,3-dipolar cycloadditions of model nitrones with dimethyl itaconate confirmed the proposed mechanism of cross-linking. Experimental Materials Acryloyl chloride (97%), crotonic acid (98%), itaconic acid (IA, 97%), methyl acrylate (99%), methyl crotonate (98%), succinic acid (SA, 99%), p