An efficient Pd–NHC catalyst system in situ generated from Na₂PdCl₄ and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

• Nan Sun,
• Meng Chen,
• Liqun Jin,
• Wei Zhao,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 1735–1744, doi:10.3762/bjoc.13.168

• Mizoroki–Heck cross-coupling reactions [64][65]. These electron-donating groups could provide a flexible environment for the Pd center and thus favoring the complexation and the migratory insertion of an alkene. Cavell reported that a pyridine functionalized Pd–NHC complex showed outstanding catalytic

Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds

• Santanu Hati,
• Ulrike Holzgrabe and
• Subhabrata Sen

Beilstein J. Org. Chem. 2017, 13, 1670–1692, doi:10.3762/bjoc.13.162

• with alkyne M. This is facilitated by coordination of L with RuII, followed by C–H activation to afford N. Migratory insertion of M on N generate O and subsequent reductive elimination of O afforded the desired compounds (Scheme 26). In another example Yuan et al. [88] demonstrated that a catalytic

Molecular recognition of N-acetyltryptophan enantiomers by β-cyclodextrin

• Spyros D. Chatziefthimiou,
• Mario Inclán,
• Petros Giastas,
• Athanasios Papakyriakou,
• Konstantina Yannakopoulou and
• Irene M. Mavridis

Beilstein J. Org. Chem. 2017, 13, 1572–1582, doi:10.3762/bjoc.13.157

• studies in aqueous solution show that both enantiomers form similar, but not identical complexes with β-CD. L-NAcTrp induces larger shifts of β-CD cavity protons, suggesting stronger binding. For both enantiomers the prevailing complexation mode involves insertion in the cavity with the N-acetyl group in

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• explain its selection for the backbone of nucleic acids. Catalysis support The promotion of some complex catalyses was also shown to occur more readily in the presence of molecular assemblies, that is, in the context of a chemical system. Such effects could be either directly linked to the insertion into

• -tuned permeability to solutes and allow for the insertion of chemical species in their hydrophobic cores, thereby enabling a multiphase chemistry. This protocell development has focused on two types of processes required for self-maintenance and self-reproduction: the synthesis of protocell building

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• and ensure the closing of the orbit, or by insertion devices, such as undulators. Undulators are a much more efficient way to produce X-ray beams and force electrons along an oscillating path in the horizontal plane (Figure 3). In this manner, the X-ray emitted at one oscillation is in phase with the

• radiation from the following oscillations, resulting in an intrinsic higher brilliance. The improvements in insertion devices have made storage rings the most versatile intense X-ray sources, and many storage rings have been constructed around the world and planning for the construction and commissioning of

From chemical metabolism to life: the origin of the genetic coding process

• Antoine Danchin

Beilstein J. Org. Chem. 2017, 13, 1119–1135, doi:10.3762/bjoc.13.111

• membrane differs during states of growth and non-growth. The former implies a constructive function of the membrane. Proteins are the effectors of this function with the key operation of allowing protein insertion within the membrane. Studies investigating spontaneous evolution of lipid vesicles showed

Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids

• Simon Drescher,
• Vasil M. Garamus,
• Christopher J. Garvey,
• Annette Meister and
• Alfred Blume

Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99

• ) [24]. However, the use of PC-C32-PC as “stabilizer” of phospholipid bilayers failed. In mixtures of PC-C32-PC with classical phospholipids, such as 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), no significant insertion of the bolalipid

• into the bilayer was observed [28]. The reason for this behaviour is that packing problems due to the mismatch between the large space requirement of the PC headgroup of PC-C32-PC and the small cross-sectional area of its single alkyl chain arise. The insertion of a PC-C32-PC molecule in a stretched

• alkyl chain of the bolalipid in order to fill the void volume. Besides heteroatoms [29][30], acetylene [31] or diacetylene groups [32], or methyl branches [31][33], also phenyl- or biphenyl rings were inserted into the long alkyl chain [34][35][36][37]. The insertion of a phenylene group led to PC

Unpredictable cycloisomerization of 1,11-dien-6-ynes by a common cobalt catalyst

• Abdusalom A. Suleymanov,
• Dmitry V. Vasilyev,
• Valentin V. Novikov,
• Yulia V. Nelyubina and
• Dmitry S. Perekalin

Beilstein J. Org. Chem. 2017, 13, 639–643, doi:10.3762/bjoc.13.62

• of this mechanism is the formation of metallacycle 6 from unsaturated cobalt(I) species [Co(PR3)2Br] and the double and the triple bond of dienyne 1 (see Supporting Information File 1 for the calculated structure of 6). Subsequent insertion of the double bond into the Co–C bond of 6 leads to the 7

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• % enantiomeric excess) from bis(α-diazo-β-keto ester) 205 [86]. The key step of this synthesis was a double intramolecular C–H insertion process catalyzed by dirhodium(II) tetrakis[N-phthaloyl-(R or S)-tert-leucinate]. The resulting spiroindanone derivative 207 obtained from the intermediate 206, underwent

• hydrogenolysis of the resulting double bond with Pd(OH)2/C, gave benzoic acid 213. Next, the latter was converted to α-diazo-β-keto ester 214 which then was submitted to the rhodium(II) acetate catalyzed intramolecular, carbon–hydrogen insertion reaction to give the spiroindane 215. Finally, the spiroindane 215

• was converted to the expected, estrogen receptor modulator 216 (Scheme 59). 3-Arylindan-1-ones 219, versatile intermediates for the synthesis of a number of biologically active compounds, have been synthesized from α-diazo-β-keto ester 218 via a intramolecular C–H insertion reaction catalyzed by the

Efficient access to β-vinylporphyrin derivatives via palladium cross coupling of β-bromoporphyrins with N-tosylhydrazones

• Vinicius R. Campos,
• Ana T. P. C. Gomes,
• Anna C. Cunha,
• Maria da Graça P. M. S. Neves,
• Vitor F. Ferreira and
• José A. S. Cavaleiro

Beilstein J. Org. Chem. 2017, 13, 195–202, doi:10.3762/bjoc.13.22

• fields, including medicine [1][2][3] , supramolecular chemistry [4][5][6] and catalysis [7][8][9][10]; their functionalization became a target for several research groups [11][12][13]. In particular, the insertion of functional groups into the macrocyclic core merits considerable attention due to the

• , affording in such way important intermediates for different synthetic strategies [4][17][18]. There are methods available allowing the insertion of alkenyl groups into porphyrin macrocycles (e.g., Heck reaction [4], metathesis [7][19][20][21], Wittig reaction [22][23]). However, palladium-catalyzed cross

Phosphated cyclodextrins as water-soluble chiral NMR solvating agents for cationic compounds

• Cira Mollings Puentes and
• Thomas J. Wenzel

Beilstein J. Org. Chem. 2017, 13, 43–53, doi:10.3762/bjoc.13.6

• that at the primary side. Native, underivatized CDs are effective chiral NMR solvating agents in water [8][9]. Water-soluble substrates with hydrophobic moieties such as aryl rings typically form inclusion complexes by insertion of the aryl ring into the CD cavity. Neutral CDs with permethylated [10

• insertion of the aryl ring into the cavity of the CDs occur which is supported by NMR measurements. In the NMR spectra the resonances of the P-CD H3 and H5 protons, which are located inside the CD cavity, are perturbed to lower frequencies in the spectra due to shielding of these protons by the inserted

Supramolecular frameworks based on [60]fullerene hexakisadducts

• Andreas Kraft,
• Johannes Stangl,
• Ana-Maria Krause,
• Klaus Müller-Buschbaum and
• Florian Beuerle

Beilstein J. Org. Chem. 2017, 13, 1–9, doi:10.3762/bjoc.13.1

• crystallization of C3 and also synthesized the next homologue C4 starting from malonate 1 [59] according to a standard two-step protocol via a sixfold Bingel reaction followed by acidic deprotection (Scheme 1). As we observed the insertion of MeOH molecules into the hydrogen-bonding network of HFF-1 [57], we also

The digital code driven autonomous synthesis of ibuprofen automated in a 3D-printer-based robot

• Philip J. Kitson,
• Stefan Glatzel and
• Leroy Cronin

Beilstein J. Org. Chem. 2016, 12, 2776–2783, doi:10.3762/bjoc.12.276

• reaction vessel for the duration of the reaction, so it was not feasible to perform the reactions under inert gas atmosphere or to completely exclude atmospheric moisture from the reactions. The reaction vessels were designed to have a small aperture wide enough for only the insertion of the dispensing

• situ during the synthesis of ibuprofen, showing the insertion of the PTFE-lined dispensing needle into the vessel. Synthetic route chosen for automated synthesis robot. The digitisation of the synthesis of ibuprofen. This flow diagram shows the individual steps of the process control software written

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

Protonated paramagnetic redox forms of di-o-quinone bridged with p-phenylene-extended TTF: A EPR spectroscopy study

• Nikolay O. Chalkov,
• Vladimir K. Cherkasov,
• Gleb A. Abakumov,
• Andrey G. Starikov and
• Viacheslav A. Kuropatov

Beilstein J. Org. Chem. 2016, 12, 2450–2456, doi:10.3762/bjoc.12.238

• ; EPR spectroscopy; extended tetrathiafulvalene; protonated semiquinone; Introduction The main idea that led to the creation of the system constructed of two o-quinone terminal moieties bridged with annulated extended tetrathiafulvalene (TTF) insertion, was an attempt to explore acceptor–donor–acceptor

• (A–D–A) systems as ligands [1]. A linear planar skeleton of the molecule with coordinating sites placed at the termini allows the construction of ordered structures using metal ions as nodes [2]. The insertion of p-phenylene in the TTF core is of special interest because it can act as a switch which

• the molecule. This allowed us to estimate the contribution of exTTF insertion to the mechanism of the electronic communication between the chelating centers of the molecule. Results and Discussion Despite almost all protonated o-semiquinones being very labile species, the direduced, diprotonated

A new paradigm for designing ring construction strategies for green organic synthesis: implications for the discovery of multicomponent reactions to build molecules containing a single ring

• John Andraos

Beilstein J. Org. Chem. 2016, 12, 2420–2442, doi:10.3762/bjoc.12.236

• thorough literature search using Reaxys indicates that cyclohexanone has been made by [5 + 1] and [4 + 2] cycloaddition strategies thus validating the patterns of assembly shown in the third and fourth entries of Scheme 1 and the fourth entry of Scheme 2. The [5 + 1] literature examples involved insertion

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• intermediate towards the diphenyl carbonate monomer. The first step is the insertion of CO2 into ethylene oxide to give ethylene carbonate, which is catalyzed by onium salts. The second step involves the transesterification of ethylene carbonate with methanol. The reaction is carried out in a continuous

• for dimethyl carbonate production: Ionic liquid-based catalysts brought about a number of improvements for the synthesis of DMC. As mentioned above, the synthesis of DMC through CO2 insertion into an epoxide and the subsequent transesterification of the formed cyclic carbonate with methanol represent

Unusual reactions of diazocarbonyl compounds with α,β-unsaturated δ-amino esters: Rh(II)-catalyzed Wolff rearrangement and oxidative cleavage of N–H-insertion products

• Valerij A. Nikolaev,
• Jury J. Medvedev,
• Olesia S. Galkina,
• Ksenia V. Azarova and
• Christoph Schneider

Beilstein J. Org. Chem. 2016, 12, 1904–1910, doi:10.3762/bjoc.12.180

• .12.180 Abstract Rh(II)-сatalyzed reactions of aroyldiazomethanes, diazoketoesters and diazodiketones with α,β-unsaturated δ-aminoesters, in contrast to reactions of diazomalonates and other diazoesters, give rise to the Wolff rearrangement and/or oxidative cleavage of the initially formed N–H-insertion

• products. These oxidation processes are mediated by Rh(II) catalysts possessing perfluorinated ligands. The formation of pyrrolidine structures, characteristic for catalytic reactions of diazoesters, was not observed in these processes at all. Keywords: diazo compounds; N–H-insertion; oxidation cleavage

• nucleophilic 1,2-migration of aryl (Ph) or alkyl (Me) group R2 occurs, producing α-oxoketene D. The latter interacts with N–H-group of the aminoester 1 to give acylamides 6a–c. Predominance of the Wolff rearrangement over typical carbenoid reactions (N–H-insertion, etc.) in the case of diazodicarbonyl

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• yield a 4,5-dihydro-1H-ketopyrrole 121 (Scheme 36) [289]. 1.2 Criegee rearrangement The Criegee rearrangement involves the transformation of a peroxide, mainly peroxyesters B, into carbonates, esters, or ketones C and alcohols D through an oxygen insertion or consecutive oxygen insertions. The

• -dioxolanes 151 are rearranged similarly to the Criegee mechanism into diketone derivatives 152 (Scheme 44) [298]. Unlike the Baeyer–Villiger rearrangement, in which only mono-O-insertion can take place, the Criegee rearrangement of peroxide 153 in an acidic medium and under solvent-free conditions does not

• have such limitations. Thus, the latter reaction can proceed sequentially through the mono-, di-, and tri-O-insertion steps with formation of ketone 154, ester 155 and carbonate ester 156 (Scheme 45) [299][300]. The selective double Criegee rearrangement next to a tertiary carbon was shown in the

On the cause of low thermal stability of ethyl halodiazoacetates

• Magnus Mortén,
• Martin Hennum and
• Tore Bonge-Hansen

Beilstein J. Org. Chem. 2016, 12, 1590–1597, doi:10.3762/bjoc.12.155

• expansion [12], and C–H insertion and Si–H insertion reactions [13]. Under Rh(II)-catalysis conditions, 2b extrudes N2 much faster than 1 (15 s vs 8 min to 50% conversion) [14]. The higher reaction rate implies a lower turnover limiting barrier in the catalytic cycle with 2b compared to 1. This example made

Flow carbonylation of sterically hindered ortho-substituted iodoarenes

• Carl J. Mallia,
• Gary C. Walter and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2016, 12, 1503–1511, doi:10.3762/bjoc.12.147

• aryl halide, an associative mechanism for the complexation of carbon monoxide on the d8 square planar intermediate would occur prior to the key migratory insertion step. In the complex, the aryl group would be oriented perpendicularly to the plane to minimise steric interactions thus placing the ortho

• yields of the array were obtained for compounds 29 and 30, demonstrating the importance of sterics and electronics adjacent to the leaving group. In both cases, the carbon monoxide insertion is assumed to be slow as both axial positions of the aryl complex would be hindered, meaning the competing proton

Ring-whizzing in polyene-PtL₂ complexes revisited

• Oluwakemi A. Oloba-Whenu,
• Thomas A. Albright and
• Chirine Soubra-Ghaoui

Beilstein J. Org. Chem. 2016, 12, 1410–1420, doi:10.3762/bjoc.12.135

• agreement with each other. Benzene–Ni(PR3)2 compounds have been known for some time [41]. An η2 geometry has been observed to be the precursor to C–F bond insertion for F6C6 complexes [42] and a number of theoretical studies have been carried out [43][44][45][46] which address this reaction. There are two

Molecular weight control in organochromium olefin polymerization catalysis by hemilabile ligand–metal interactions

• Stefan Mark,
• Hubert Wadepohl and
• Markus Enders

Beilstein J. Org. Chem. 2016, 12, 1372–1379, doi:10.3762/bjoc.12.131

• chain transfer to aluminum. On the other hand, the donors are weak enough in order to be displaced by ethylene monomers so that the insertion polymerization can proceed with high turnover numbers. With this concept, it is possible to tune the catalyst behavior in terms of the molecular weight they

Application of Cu(I)-catalyzed azide–alkyne cycloaddition for the design and synthesis of sequence specific probes targeting double-stranded DNA

• Svetlana V. Vasilyeva,
• Vyacheslav V. Filichev and
• Alexandre S. Boutorine

Beilstein J. Org. Chem. 2016, 12, 1348–1360, doi:10.3762/bjoc.12.128

• synthesis of conjugates of pyrrole–imidazole polyamide minor groove binders (MGB) with fluorophores and with triplex-forming oligonucleotides (TFOs). Diverse bifunctional linkers were synthesized and used for the insertion of terminal azides or alkynes into TFOs and MGBs. The formation of stable triple

• fluorescent probes via their labeling by commercial and "home-made" fluorescent dyes bearing azide groups. It was noted that yields of alkyne-modified MGBs were higher (50–83%) compared to those of azide modified MGBs (≈40%). The other variant for insertion of terminal azide or alkyne groups into the

• indicate that the presence of the triazole moiety in the linker slightly perturbs the triplex formation. Conclusion Diverse bifunctional linkers of different length, hydrophobicity and flexibility for insertion of terminal azide or alkyne groups into biomolecules were synthesized and applied for

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• process involves an initial nucleophilic addition of phosphite to carbodiimide 197 affording intermediate 200 which undergoes an oxidative addition of Pd(0) to give Pd(II) species 201. Subsequently, the insertion of isocyanide 199 to species 201 affords intermediate 202, which finally generates