New aryloxybenzylidene ruthenium chelates – synthesis, reactivity and catalytic performance in ROMP

• Patrycja Żak,
• Szymon Rogalski,
• Mariusz Majchrzak,
• Maciej Kubicki and
• Cezary Pietraszuk

Beilstein J. Org. Chem. 2015, 11, 1910–1916, doi:10.3762/bjoc.11.206

• catalyst is presented. ROMP of monomer 15. Conditions: CDCl3, 40 °C, 0.08 M, [15]:[Ru] = 200. ROMP of monomer 15. Conditions: CDCl3, 23 °C, 0.08 M, [15]:[Ru] = 200. A perspective view of complex 16, the ellipsoids are drawn at the 50% probability level. Hydrogen atoms are drawn as spheres of arbitrary

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

• in addition to the equipment. From an academic perspective this is a positive and beneficial contribution to the progression of the subject, however, this can significantly restrict the translational value of the methodology with respect to adoption or convenient uptake by industry. Commonly industry

• the reactor should be made here from a scale-up perspective as this was not explored in the paper. Overall, this small scale syringe pump based set-up enabled the preparation of rufinamide (95) within ~11 minutes processing time and with a productivity of ~0.22 g/h, although this does not take into

An intramolecular C–N cross-coupling of β-enaminones: a simple and efficient way to precursors of some alkaloids of Galipea officinalis

• Hana Doušová,
• Radim Horák,
• Zdeňka Růžičková and
• Petr Šimůnek

Beilstein J. Org. Chem. 2015, 11, 884–892, doi:10.3762/bjoc.11.99

• molecules from a C–N cross-coupling perspective. There are relatively few works (about ten) dealing with these very useful molecules [35][36][37][38][39][40][41][42][43][44][45][46], in comparison to the hundreds of papers dedicated to the other substrates. Due to their electronic nature, β-enaminones can

Hydrogenation of unactivated enamines to tertiary amines: rhodium complexes of fluorinated phosphines give marked improvements in catalytic activity

• Sergey Tin,
• Tamara Fanjul and
• Matthew L. Clarke

Beilstein J. Org. Chem. 2015, 11, 622–627, doi:10.3762/bjoc.11.70

• require quite different ligands to those needed for enamide hydrogenation. From a synthetic perspective, large scale reduction processes generally prefer the use of hydrogen gas to any other reductant, since it potentially saves on cost, waste, atom-economy, solvent and water use; the catalysts identified

Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

• Tor E. Kristensen

Beilstein J. Org. Chem. 2015, 11, 446–468, doi:10.3762/bjoc.11.51

• for many applications, particularly within the academic sector. Purification by flash column chromatography then easily becomes a practical, standardized procedure. If a longer historical perspective is adopted, dating prior to the advent of widespread flash column chromatography, one will realize

A simple and efficient method for the preparation of 5-hydroxy-3-acyltetramic acids

• Johanna Trenner and
• Evgeny V. Prusov

Beilstein J. Org. Chem. 2015, 11, 323–327, doi:10.3762/bjoc.11.37

• natural products as delaminomycin A [1], embellicin A [2] and integramycin [3] (Figure 1). Additionally, 5-heterosubstituted-3-acyltetramic acids were recently identified by Moloney as perspective lead structures for the development of novel antibacterial compounds [4]. Intrigued by their potential

Natural phenolic metabolites with anti-angiogenic properties – a review from the chemical point of view

• Qiu Sun,
• Jörg Heilmann and
• Burkhard König

Beilstein J. Org. Chem. 2015, 11, 249–264, doi:10.3762/bjoc.11.28

• from preexisting ones. Under physiological conditions, angiogenesis is vital for foetal development, tissue regeneration and wound healing. From a pathophysiologic perspective, massive vascular growth or abnormal shape formation promotes many ailments including cancer, inflammation, and eye illnesses

Anion effect controlling the selectivity in the zinc-catalysed copolymerisation of CO₂ and cyclohexene oxide

• Sait Elmas,
• Muhammad Afzal Subhani,
• Walter Leitner and
• Thomas E. Müller

Beilstein J. Org. Chem. 2015, 11, 42–49, doi:10.3762/bjoc.11.7

• ) [21][22][23][24] atom (Type II). Most catalysts based on Salen-type ligands are substrate specific and are most efficient for the copolymerisation of CO2 with propylene oxide (PO). The use of zinc-based catalysts of Type I appears more favourable from an environmental perspective compared to the use

First chemoenzymatic stereodivergent synthesis of both enantiomers of promethazine and ethopropazine

• Paweł Borowiecki,
• Daniel Paprocki and
• Maciej Dranka

Beilstein J. Org. Chem. 2014, 10, 3038–3055, doi:10.3762/bjoc.10.322

The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

• Volodymyr V. Tkachenko,
• Elena A. Muravyova,
• Sergey M. Desenko,
• Oleg V. Shishkin,
• Svetlana V. Shishkina,
• Dmytro O. Sysoiev,
• Thomas J. J. Müller and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2014, 10, 3019–3030, doi:10.3762/bjoc.10.320

• spectrum of biological activity [5][6], which led to choose acetoacetamides as perspective methylene-active compounds for further studies of multicomponent reactions. The interactions of 3-oxobutanamides with aldehydes and a number of aminoazoles, namely 3-amino-1,2,4-triazoles [7][8][9][10][11], 5

Modification of physical properties of poly(L-lactic acid) by addition of methyl-β-cyclodextrin

• Toshiyuki Suzuki,
• Ayaka Ei,
• Yoshihisa Takada,
• Hiroki Uehara,
• Takeshi Yamanobe and
• Keiko Takahashi

Beilstein J. Org. Chem. 2014, 10, 2997–3006, doi:10.3762/bjoc.10.318

• superior to MeCD, MeCD is a biobased material and is thus advantageous from an environmental perspective. These TGA results show that MeCD acts as a plasticizer for PLLA, and the fraction of the amorphous phase increases. Since the Tg of the samples may be affected by the MeCD addition, DSC measurements

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

• Bradley D. Rose,
• Peter J. Santa Maria,
• Aaron G. Fix,
• Chris L. Vonnegut,
• Lev N. Zakharov,
• Sean R. Parkin and
• Michael M. Haley

Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219

• transport these are the orbitals that the extra electron would occupy. The Kohn–Sham LUMO density in Figure 3 is predominately located on the indacene moiety and the oxygen. From this perspective the best candidates for n-channel OFET materials would have large overlap between the indacene moiety and oxygen

Multichromophoric sugar for fluorescence photoswitching

• Stéphane Maisonneuve,
• Rémi Métivier,
• Pei Yu,
• Keitaro Nakatani and
• Juan Xie

Beilstein J. Org. Chem. 2014, 10, 1471–1481, doi:10.3762/bjoc.10.151

• molecule. This is valuable in terms of photon (thus energy) saving, since “switching a few photochromes leads to quenching many fluorophores”. In this perspective, we decided to design a multichromophoric glycopyranoside bearing three DCM fluorophores and one photochromic bis(dithiazole)ethane [14][15][16

Rasta resin–triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions

• Xuanshu Xia and
• Patrick H. Toy

Beilstein J. Org. Chem. 2014, 10, 1397–1405, doi:10.3762/bjoc.10.143

• ; polymer-supported reagent; rasta resin; triphenylphosphine oxide; Introduction One of the major drawbacks of the Wittig [1] and Mitsunobu [2][3] reactions is that they result in the formation of a stoichiometric quantity of triphenylphosphine oxide (1) as a byproduct. From an atom economy perspective

Automated solid-phase peptide synthesis to obtain therapeutic peptides

• Veronika Mäde,
• Sylvia Els-Heindl and
• Annette G. Beck-Sickinger

Beilstein J. Org. Chem. 2014, 10, 1197–1212, doi:10.3762/bjoc.10.118

• significantly smaller in size and hence, easier and cheaper to synthesize using chemical strategies [5]. Thereby, they provide a vast perspective for novel drug design. Table 1 summarizes valuable virtues and pivotal shortcomings of therapeutic peptides compared to traditional small organic molecules. The high

Allenylphosphine oxides as simple scaffolds for phosphinoylindoles and phosphinoylisocoumarins

• G. Gangadhararao,
• Ramesh Kotikalapudi,
• M. Nagarjuna Reddy and
• K. C. Kumara Swamy

Beilstein J. Org. Chem. 2014, 10, 996–1005, doi:10.3762/bjoc.10.99

• ; propargyl alcohols; Introduction Allenes, by virtue of cumulative double bonds that facilitate reactions with diverse classes of substrates, are versatile building blocks from a synthetic perspective [1][2]. They are also found in many natural products, pharmaceuticals [3] and molecular materials [4]. Thus

Molecular architecture with carbohydrate functionalized β-peptides adopting 3₁₄-helical conformation

• Nitin J. Pawar,
• Navdeep S. Sidhu,
• George M. Sheldrick,
• Dilip D. Dhavale and
• Ulf Diederichsen

Beilstein J. Org. Chem. 2014, 10, 948–955, doi:10.3762/bjoc.10.93

• , galactose and xylose derivatives were incorporated as sugar units in rigid peptide templates. Keeping the proper β3-configuration for getting a β-peptide 314-helix (2–6) the isopropylidene protecting group and an anomeric acetal are structurally well tolerated. An additional perspective emerged from the

Modulating NHC catalysis with fluorine

• Yannick P. Rey and
• Ryan Gilmour

Beilstein J. Org. Chem. 2013, 9, 2812–2820, doi:10.3762/bjoc.9.316

• associated with H→F substitution, together with the polarised nature and stability of aliphatic C–F bonds, render this unit attractive from the perspective of molecular design [4]. The low-lying antibonding orbital (σC–F*) can interact with an array of vicinal substituents ranging from non-bonding electron

Flow microreactor synthesis in organo-fluorine chemistry

• Hideki Amii,
• Aiichiro Nagaki and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2013, 9, 2793–2802, doi:10.3762/bjoc.9.314

• stability of fluorine-containing intermediates and low selectivity (chemo-, regio-, and/or stereo-) of the reactions have disturbed the progress of synthesis of fluorochemicals. New methodologies that can cure the weak points in synthesizing fluoro-organic compounds would open up a new perspective for

Flow synthesis of phenylserine using threonine aldolase immobilized on Eupergit support

• Jagdish D. Tibhe,
• Hui Fu,
• Timothy Noël,
• Qi Wang,
• Jan Meuldijk and
• Volker Hessel

Beilstein J. Org. Chem. 2013, 9, 2168–2179, doi:10.3762/bjoc.9.254

• industrial perspective, Hessel et al. have analyzed the patent situation in the field of microreaction technology [23]. In extension to such fine-chemical and pharmaceutical applications being investigated for almost 20 years, the quite recent introduction of microfluidic devices in bioprocess

• which is currently been investigated in our laboratories. Taking into account the experimentally derived flow performance mentioned above, the calculated TA-enzyme based microreactor productivity was found to be 5.4 mg/h. From an industrial perspective on microreactors, it is reasonable to assume that

Synthesis of enantiomerically pure N-(2,3-dihydroxypropyl)arylamides via oxidative esterification

• Akula Raghunadh,
• Satish S More,
• T. Krishna Chaitanya,
• Yadla Sateesh Kumar,
• Suresh Babu Meruva,
• L. Vaikunta Rao and
• U. K. Syam Kumar

Beilstein J. Org. Chem. 2013, 9, 2129–2136, doi:10.3762/bjoc.9.250

• opening of chiral epoxide with an aryl or heteroaryl aldehyde by oxidative esterification. This method may prove significant from the perspective of green chemistry. The application of this methodology for the synthesis of several bicyclic frameworks and natural products is under progress, and will be

An investigation of the observed, but counter-intuitive, stereoselectivity noted during chiral amine synthesis via N-chiral-ketimines

• Thomas C. Nugent,
• Richard Vaughan Williams,
• Andrei Dragan,
• Alejandro Alvarado Méndez and
• Andrei V. Iosub

Beilstein J. Org. Chem. 2013, 9, 2103–2112, doi:10.3762/bjoc.9.247

• addition to imines [31][32] continue to be refined and relied on. Furthermore, enzymatic methods can offer competitive advantages that cannot be overlooked [33][34][35]. With this perspective, it is perhaps unsurprising that methods utilizing imines with chiral amine auxiliaries, i.e. N-chiral imines, can

• this broader perspective, insights into the variables affecting diastereoselective amine synthesis, via imines, will continue to be of importance and is the focus of this article. Results and Discussion When reducing N-chiral imines of (R)- or (S)-phenylethylamine (PEA), the facial preference is

• this fact for the first time as a recognizable trend and note it for two types of precursor ketones: methyl alkyl ketones lacking α-branching in the alkyl substituent R (Figure 1) and an aromatic alkyl ketone, i.e. phenyl n-propyl ketone. Historical perspective Previous researchers investigating the

Raman spectroscopy as a tool for monitoring mesoscale continuous-flow organic synthesis: Equipment interface and assessment in four medicinally-relevant reactions

• Trevor A. Hamlin and
• Nicholas E. Leadbeater

Beilstein J. Org. Chem. 2013, 9, 1843–1852, doi:10.3762/bjoc.9.215

• interfacing a Raman spectrometer with a scientific microwave unit [31]. This has allowed us to monitor reactions from both a qualitative [32][33][34][35] and quantitative [36][37] perspective. A recent report of the use of Raman spectroscopy for monitoring a continuous-flow palladium-catalyzed cross-coupling

The rapid generation of isothiocyanates in flow

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 1613–1619, doi:10.3762/bjoc.9.184

• within a pseudo-/continuous flow process [11][12]. From a synthesis perspective the majority of these endeavours have been directed at enhancing specific reaction safety profiles, identifying new reaction sequences or generating improvements to well-known yet cumbersome transformations [13][14][15][16

A³-Coupling catalyzed by robust Au nanoparticles covalently bonded to HS-functionalized cellulose nanocrystalline films

• Jian-Lin Huang,
• Derek G. Gray and
• Chao-Jun Li

Beilstein J. Org. Chem. 2013, 9, 1388–1396, doi:10.3762/bjoc.9.155

• reaction; cellulose nanocrystallites (CNCs) films; gold catalysis; water or without solvent; Introduction Organic synthesis is usually performed in organic solvents; however, from a green chemistry perspective, evaporation and discharge of organic solvents not only generates chemical waste but also causes