Extrusion – back to the future: Using an established technique to reform automated chemical synthesis

• Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 65–75, doi:10.3762/bjoc.13.9

• greater at 3250,000 kg m−3 d−1, whereas batch synthesis was determined to be 500 kg m−3 d−1 [44]. Furthermore, these materials (particularly choline chloride/zinc chloride (1:2)) are known to be incredibly viscous and so very difficult to transport from the batch mixer into storage containers, but

Computational methods in drug discovery

• Sumudu P. Leelananda and
• Steffen Lindert

Beilstein J. Org. Chem. 2016, 12, 2694–2718, doi:10.3762/bjoc.12.267

• molecules and target proteins. PubChem, a small molecule repository is available through NIH which contains millions of biologically relevant small molecules [78]. ZINC is a virtual high-throughput screening compound library which is a free public resource [79][80]. This database contains over 35 million

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

• initiated from known iododerivatives 13 and 14, prepared from suitably protected carbohydrates (Scheme 3) [45][46][47]. Each of these compounds was subjected to the zinc-mediated fragmentation, followed by the Jones oxidation. The resulting acid (not purified) was transformed into a Weinreb amide. As a

Effects of solvent additive on “s-shaped” curves in solution-processed small molecule solar cells

• John A. Love,
• Shu-Hua Chou,
• Ye Huang,
• Guilllermo C. Bazan and
• Thuc-Quyen Nguyen

Beilstein J. Org. Chem. 2016, 12, 2543–2555, doi:10.3762/bjoc.12.249

• ITO/ZnO/PEIE/p-SIDT(FBTThCA8)2:PC71BM/MoO3/Al where PEIE refers to ethoxylated polyethylenimine. The cathode was cast from a sol–gel of zinc acetate, and thermally converted to ZnO in air as described in literature [69]. A thin (10 nm) layer of PEIE has been shown in the past to improve contact by

Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols

• Katrina Tait,
• Oday Alrifai,
• Rebecca Boutin,
• Jamie Haner and
• William Tam

Beilstein J. Org. Chem. 2016, 12, 2189–2196, doi:10.3762/bjoc.12.209

• the use of platinum catalysts [19] or palladium catalysts with zinc co-catalyst with phenol nucleophiles [20]. Meanwhile, anti-stereoisomeric products 5 and 6 are obtained when copper catalysts are used with alkyl nucleophiles [21], if rhodium [22] or iridium catalysts are used in the presence of

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

• Dominik Urselmann,
• Konstantin Deilhof,
• Bernhard Mayer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

• to form self-assembled monolayers on gold [69][70][71] as well as on zinc and iron oxide surfaces [72]. Conceptually, thienyl-bridged oligophenothiazines can be considered as a novel type of structurally well-defined electron-rich oligophenothiazine–thiophene hybrids (Figure 1). Thereby, the strong

Economical and scalable synthesis of 6-amino-2-cyanobenzothiazole

• Jacob R. Hauser,
• Hester A. Beard,
• Mary E. Bayana,
• Katherine E. Jolley,
• Stuart L. Warriner and
• Robin S. Bon

Beilstein J. Org. Chem. 2016, 12, 2019–2025, doi:10.3762/bjoc.12.189

• reported procedures with zinc powder and ammonium chloride [7]. It resulted in more consistent yields, an easier work-up, and no persistent contamination of 8 with nitroso intermediates [6]. The reduction step was accomplished on a 1 g and 5 g scale isolating ACBT 8 by filtration through a short silica

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• Homoleptic zinc(II) complexes of di(phenylacetylene)azadipyrromethene (e.g., Zn(WS3)2) are potential non-fullerene electron acceptors for organic photovoltaics. To tune their properties, fluorination of Zn(WS3)2 at various positions was investigated. Three fluorinated azadipyrromethene-based ligands were

• chelated with zinc(II) and BF2+ and the optical and electrochemical properties were studied. Fluorination had little effect on the optical properties of both the zinc(II) and BF2+ complexes, with λmax in solution around 755 nm and 785 nm, and high molar absorptivities of 100 × 103 M−1cm−1 and 50 × 103 M

• absorber; non-fullerene acceptor; zinc(II) complex; Introduction Azadipyrromethenes (ADPs) (Figure 1a) are a class of monoanionic bidentate ligands with strong absorption in the visible and near IR range. Their absorbance and emission properties can be readily tuned through structural modifications and

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

• an elegant investigation on the model transesterification of ethyl acetate with methanol [9]. The production of biodiesel blends is another sector in which the catalytic transesterification is extensively used. In particular, heterogeneous catalysts including calcium, manganese and zinc oxides as

• the ionic liquids by monitoring the IR bands in the presence of pyridine as a probe molecule. The highest conversions (30–39%) of phenol and the best selectivity toward DPhC were achieved using N-methyl-2-pyrrolidone hydrogen sulfate [NMP][HSO4] and choline chloride zinc chloride ([ChCl][ZnCl2]). The

Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

• Élise Euvrard,
• Nadia Morin-Crini,
• Coline Druart,
• Justine Bugnet,
• Bernard Martel,
• Cesare Cosentino,
• Virginie Moutarlier and
• Grégorio Crini

Beilstein J. Org. Chem. 2016, 12, 1826–1838, doi:10.3762/bjoc.12.172

• their own treatment plants, generally physicochemical decontamination steps, the DWs still contain non-negligible amounts of pollutants. Among them, metals (in particular chromium, nickel and zinc) are commonly found at concentrations in the range of milligrams per liter, and organic molecules, such as

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

• Mannich-type reaction; rhodium–hydride; zinc enolate; Introduction The Mannich reaction is an important and classical C–C bond-forming reaction between an enolizable carbonyl compound and an imine to give the corresponding β-aminocarbonyl compound. For example, Shibasaki and his colleague reported the

• to assist in the formation of the iminium salt in an effort to improve the reactivity. It was clear that Et2Zn was only working as a hydride source but was ineffective as the Lewis acid. Instead when zinc chloride (ZnCl2) was added into the mixture, the yield was improved to 30% (Table 2, entry 5

• enolate 7 involved the 1,4-reduction of α,β-unsaturated ester 2 by 6 and the transmetalation with a zinc species to give the Reformatsky-type reagent Int A. This intermediate Int A reacts immediately with the imine to give the corresponding intermediate Int B. Subsequently, intramolecular cyclization of

Star-shaped and linear π-conjugated oligomers consisting of a tetrathienoanthracene core and multiple diketopyrrolopyrrole arms for organic solar cells

• Hideaki Komiyama,
• Chihaya Adachi and
• Takuma Yasuda

Beilstein J. Org. Chem. 2016, 12, 1459–1466, doi:10.3762/bjoc.12.142

• in detergent solution, deionized water, acetone, and isopropanol for 15 min each, and then subjected to UV/ozone treatment for 30 min. A thin layer (~30 nm) of ZnO was prepared by spin-coating (at 5000 rpm) a precursor solution of zinc acetate (0.50 g) and ethanolamine (0.14 g) in 2-methoxyethanol (5

Cyclisation mechanisms in the biosynthesis of ribosomally synthesised and post-translationally modified peptides

• Andrew W. Truman

Beilstein J. Org. Chem. 2016, 12, 1250–1268, doi:10.3762/bjoc.12.120

• ” was a zinc-containing cyclase, and the “D-protein” possesses ATPase activity. The requirement for ATP turnover during cyclisation led to the hypothesis that the D-protein was a docking protein that regulates heterocyclase activity [33], while the presence of zinc in the C-protein pointed towards a

• catalysed by a zinc-dependent LanC cyclase (NisC). In nisin biosynthesis, the precursor peptide, NisA, is dehydrated 8 times by NisB [50], and this has been shown to occur with directionality from the N- to C-terminus of the core peptide [51]. In vitro reconstitution of NisB activity with the nisin

• central kinase domain catalyses phosphorylation and an N-terminal lyase domain catalyses elimination [58]. Both class III and IV synthetases have C-terminal LanC-like cyclase domains, but class III enzymes lack the three conserved residues that bind zinc in the other classes [57], which is surprising

Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups

• Jakub Saadi,
• Christoph Bentz,
• Kai Redies,
• Dieter Lentz,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2016, 12, 1236–1242, doi:10.3762/bjoc.12.118

• of organometallics such as lithium, magnesium or zinc organic compounds to carbonyl groups leading to alcohols is an important standard operation in organic synthesis providing high stereoselectivities in many cases. The in situ generation of the nucleophilic species from the corresponding organic

Synthesis, fluorescence properties and the promising cytotoxicity of pyrene–derived aminophosphonates

• Jarosław Lewkowski,
• Maria Rodriguez Moya,
• Anna Wrona-Piotrowicz,
• Janusz Zakrzewski,
• Renata Kontek and
• Gabriela Gajek

Beilstein J. Org. Chem. 2016, 12, 1229–1235, doi:10.3762/bjoc.12.117

• -yl)methyleneamine [17], a N-(1-pyrene)methylideneglucosamine mercury complex [18], a N-(pyren-1-ylidene)-2-hydroxyaniline-copper(II) and -zinc(II) complexes [19] or N-(pyren-1-ylidene)-4-carboxyaniline-Fe(II) and -Cr(III) complexes [20]. Several phosphorus-supported ligands containing a pyrene-1

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

• determining enantioselectivity? To answer these questions, we synthesized a 1,6-enyne containing an enantioenriched propargyl alcohol using our group’s zinc ProPhenol chemistry (Scheme 7). By employing the opposite enantiomers of the ProPhenol catalyst, either enantiomer of propargyl alcohol can be accessed

• -catalyzed addition of zinc acetylide to acetaldehyde for the synthesis of a chiral 1,6-enyne substrate. Curtin–Hammitt scenario of redox bicycloisomerization in acetone. Initial result for the asymmetric redox bicycloisomerization of 1,7-enyne 13 with chiral CpRu-sulfoxide complex 1 and the effect of added

1H-Imidazol-4(5H)-ones and thiazol-4(5H)-ones as emerging pronucleophiles in asymmetric catalysis

• Antonia Mielgo and
• Claudio Palomo

Beilstein J. Org. Chem. 2016, 12, 918–936, doi:10.3762/bjoc.12.90

• . The authors found that whilst the best results for allylation of oxazol-4-(5H)-ones were achieved from zinc enolates, thiazol-4-(5H)-ones produced the best outcome when the magnesium enolate was used. After optimization it was shown that the reaction was efficient with different cinnamyl tert-butyl

Recent advances in C(sp³)–H bond functionalization via metal–carbene insertions

• Bo Wang,
• Di Qiu,
• Yan Zhang and
• Jianbo Wang

Beilstein J. Org. Chem. 2016, 12, 796–804, doi:10.3762/bjoc.12.78

• the methane C–H bond. As a result, the side reactions of the highly active metallocarbene intermediate override the C–H insertion. Zinc catalysts, which were seldom used for metal–carbene C–H insertions, have been recently explored in the C–H insertion between EDA with alkanes [45]. A detailed

• computational study of the likely intermediate suggests that it is best described as a zinc-bound carbocation rather than a zinc carbene (Scheme 12). Notably, Zn is a cheap, earth-abundant 3d metal, thus making it attractive as catalyst for C–H bond functionalization. Conclusion The intermolecular metal–carbene

From steroids to aqueous supramolecular chemistry: an autobiographical career review

• Bruce C. Gibb

Beilstein J. Org. Chem. 2016, 12, 684–701, doi:10.3762/bjoc.12.69

• zinc complexes (Figure 3) as mimics of the enzyme Carbonic Anhydrase. The ligands for these complexes are notoriously difficult to work with chromatographically, but I managed to synthesize a few derivatives that not only replicated the zinc binding site, but also some of the functionality that

• ‘dangles’ above the zinc-bound water in the crystal structure of the enzyme. In addition to synthesis, the project also involved a good deal of potentiometry, and this began to teach me that synthesizing enzyme mimics was a difficult challenge of balancing the need to create functionality for the active

• Nature does. Arch critic that I am, I turned on my own research; “how can we ever expect to get the zinc-bound water in our complexes to be the strong acid it is in Carbonic Anhydrase if we’re not fully taking into account context?” Jim gave me his bemused/slightly-exasperated/are you kidding me kind of

Regioselective palladium-catalyzed ring-opening reactions of C1-substituted oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylates

• Michael Edmunds,
• Mohammed Abdul Raheem,
• Rebecca Boutin,
• Katrina Tait and
• William Tam

Beilstein J. Org. Chem. 2016, 12, 239–244, doi:10.3762/bjoc.12.25

• requirement for Et3N, zinc and high temperatures had previously been determined in related reactions (Table 1) [15]. C1-methyl-substitued oxanorbornadiene 2a was selected for the optimization study due to the ease at which it can be synthesized in larger quantities. The palladium catalysts were selected based

• % respectively (Table 1, entries 9 and 4). The Lewis acid additives gave a large range of yields (Table 1, entries 10–14). Iron and aluminium chlorides gave low yields (22%, Table 1, entry 10 and 29%, entry 11), zirconium chloride and zinc iodide gave moderate yields (47%, Table 1, entry 12 and 48%, entry 13

• ) and copper chloride and zinc chloride gave the highest yields (85%, Table 1, entry 14 and 88%, entry 4). The combination of PdCl2(PPh3)2, THF, and zinc chloride resulted in the highest conversion to the ring-opened product. Once the optimized conditions were found, 2a was reacted with a variety of

Diastereoselective Ugi reaction of chiral 1,3-aminoalcohols derived from an organocatalytic Mannich reaction

• Samantha Caputo,
• Andrea Basso,
• Lisa Moni,
• Renata Riva,
• Valeria Rocca and
• Luca Banfi

Beilstein J. Org. Chem. 2016, 12, 139–143, doi:10.3762/bjoc.12.15

• in aprotic solvents such as THF at low temperature, and therefore the background, uncatalyzed reaction should not interfere. As shown in Table 1, the best results were achieved by using 1 equiv of zinc bromide (Table 1, entry 8), affording a 10:1 diastereomeric ratio and an excellent overall yield

• . Other zinc-based catalysts were less efficient, whereas most of the other tested Lewis acids failed to promote the reaction at all. The use of Lewis acids in methanol or trifluoroethanol afforded lower yields with no improvement of diastereoselection. It is worth noting that a 10:1 diastereoselectivity

Enantioselective additions of copper acetylides to cyclic iminium and oxocarbenium ions

• Jixin Liu,
• Srimoyee Dasgupta and
• Mary P. Watson

Beilstein J. Org. Chem. 2015, 11, 2696–2706, doi:10.3762/bjoc.11.290

• particular, seminal reports by the Carreira lab demonstrated that the use of stoichiometric metal acetylides was not required to achieve addition to aldehydes; catalytic Zn(OTf)2 and N-methylephedrine in combination with Et3N enabled in situ formation of chiral zinc acetylides, which underwent addition to

Inclusion complexes of 2-methoxyestradiol with dimethylated and permethylated β-cyclodextrins: models for cyclodextrin–steroid interaction

• Mino R. Caira,
• Susan A. Bourne,
• Halima Samsodien and
• Vincent J. Smith

Beilstein J. Org. Chem. 2015, 11, 2616–2630, doi:10.3762/bjoc.11.281

• of fusion of indium (156.6 °C) and zinc (419.5 °C). The heat flow calibration was based on the value of ΔH of fusion of indium (28.62 J/g). Samples in the form of fine powders (mass range 2–5 mg) were sealed in crimped, vented aluminium pans and were heated at 10 K/min, with a sealed, empty pan as

Smart molecules for imaging, sensing and health (SMITH)

• Bradley D. Smith

Beilstein J. Org. Chem. 2015, 11, 2540–2548, doi:10.3762/bjoc.11.274

• on the cell surface during the process of apoptosis or programmed cell death. Thus, phosphatidylserine is an excellent biomarker of cell death and an attractive target for molecular imaging. We reasoned that synthetic anion receptors such as zinc dipicolylamine (ZnDPA) coordination complexes would

Diversity-oriented synthesis of analogues of the novel macrocyclic peptide FR-225497 through late stage functionalization

• Jyotiprasad Mukherjee,
• Suman Sil and
• Shital Kumar Chattopadhyay

Beilstein J. Org. Chem. 2015, 11, 2487–2492, doi:10.3762/bjoc.11.270

• of the spacer region as well as the metal-binding domain attached to a particular surface recognition part present in the class of these compounds since histone deacetylase activity has been correlated to zinc-binding ability of the 8-oxo moiety in some of such compounds [25]. Moreover, the