Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Volume 2015, Issue 1
Sudheesh T. Sivanandan, Ashna Shaji, Ibrahim Ibnusaud, Carin C. C. Johansson Seechurn and Thomas J. Colacot
Article first published online: 17 DEC 2014 | DOI: 10.1002/ejoc.201490106
The cover picture shows the scope of the α-arylation reaction of carbonyl compounds, such as ketones, aldehydes, esters and amides in the total syntheses of natural products and active pharmaceutical ingredients (API). This is exciting, because α-arylation reactions have emerged recently as one of the new trends in cross-coupling reactions, in which the CH at the α position of the carbonyl group undergoes functionalization by enolization in the presence of a base, followed by a C–C coupling under the influence of a metal catalyst, typically Pd. The potential of this powerful methodology will be enormous for key steps in organic synthesis for small and large molecules. Details are presented in the Microreview by T. J. Colacot et al. on 38 ff.
Article first published online: 17 DEC 2014 | DOI: 10.1002/ejoc.201403496
Editor-in-chief Haymo Ross looks back at the important events for EurJOC in 2014, including the move to Editorial Manager, and gives a preview of what is to come in 2015.
Article first published online: 17 DEC 2014 | DOI: 10.1002/ejoc.201490107
Article first published online: 17 DEC 2014 | DOI: 10.1002/ejoc.201490105
Donald R. Wenz and Javier Read de Alaniz
Article first published online: 9 SEP 2014 | DOI: 10.1002/ejoc.201402825
We describe three general approaches to the formation of fully substituted quaternary carbon stereocenters by means of the Nazarov cyclization.
Article first published online: 19 NOV 2014 | DOI: 10.1002/ejoc.201403301
Metal-catalyzed α-arylation of carbonyl compounds has become a powerful tool for organic chemists to construct carbon-carbon bonds through C–H functionalization based on enolization. This microreview highlights recent applications of α-arylation in total syntheses both of natural products and of active pharmaceutical ingredients (APIs).
Tryfon Zarganes-Tzitzikas, Pravin Patil, Kareem Khoury, Eberhardt Herdtweck and Alexander Dömling
Article first published online: 17 NOV 2014 | DOI: 10.1002/ejoc.201403401
A novel compound class of tetrazole–diketopiperazines is described. Two multicomponent reactions are used during the synthesis: the Ugi tetrazole four-component reaction (4CR) and the classical intramolecular Ugi 4CR. Tetrazole–diketopiperazines comprise analogs of and are bioisosteric to bioactive diketopiperazines. The scaffold is currently produced to fill the screening deck of the European Lead Factory.
Alexandra Jakab, Zoltán Dalicsek and Tibor Soós
Article first published online: 31 OCT 2014 | DOI: 10.1002/ejoc.201402586
Application of a unique, thermally stable, and air-stable Pd0 catalyst for the direct arylation of heteroarenes is described. The combination of only 0.5–2 mol-% of the Pd0 complex possessing an electron-deficient fluorinated phosphine ligand with a substoichiometric quantity of pivalic acid (PivOH) generates an efficient system to promote the C–H activation of a broad range of heteroarenes.
Alexandra Jakab, Zoltán Dalicsek, Tamás Holczbauer, Andrea Hamza, Imre Pápai, Zoltán Finta, Géza Timári and Tibor Soós
Article first published online: 25 NOV 2014 | DOI: 10.1002/ejoc.201403214
An unprecedentedly thermo- and air-stable Pd0 complex from readily available electron-poor trifluoromethylated phosphine is reported. The stability of the complex is associated with unusually strong ligand–ligand noncovalent interactions. The unique stability of the complex and the presence of hydrophobic structural elements are exploited in catalytic Suzuki–Miyaura coupling reactions.
Daniela Sustac Roman, Valentin Poiret, Guillaume Pelletier and André B. Charette
Article first published online: 21 NOV 2014 | DOI: 10.1002/ejoc.201403268
The RuII-catalyzed direct ortho-arylation of C-3-substituted imidazo[1,5-a]azines with (hetero)aryl halides is investigated. Multiple arylations are performed sequentially in a one-pot procedure with the use of RuII and PdII catalysts.
Pablo Ortiz, Ana M. del Hoyo and Syuzanna R. Harutyunyan
Article first published online: 12 NOV 2014 | DOI: 10.1002/ejoc.201403297
The first example of the direct catalytic asymmetric alkylation of diaryl ketones by using Grignard reagents is reported. The low reactivity and similarity of the enantiotopic faces of the substrates is partially overcome, which results in the corresponding enantioenriched diarylmethanol core.
Carl Albrecht Dannenberg, Vincent Bizet, Liang-Hua Zou and Carsten Bolm
Article first published online: 6 NOV 2014 | DOI: 10.1002/ejoc.201403352
The transition-metal-free oxidative iodination of 2-substituted 1,3,4-oxadiazoles is developed to provide products in moderate to good yields with NaI as the halogen source and Selectfluor as the oxidant. Neither anhydrous conditions nor an inert atmosphere is required, which renders this process synthetically attractive.
Terry McCallum, Ekaterina Slavko, Mathieu Morin and Louis Barriault
Article first published online: 12 NOV 2014 | DOI: 10.1002/ejoc.201403351
While exploring orthogonal reactivity with [Au2(dppm)2]Cl2 [dppm = 1,1-bis(diphenylphosphino)methane], the high-yielding photochemical bromination of alcohols was found. The simplicity of this reaction makes it a perfect match for combining bromination with reductive dehalogenation through photoredox catalysis. The highly efficient one-pot reductive deoxygenation protocol for primary alcohols is presented.
Santosh J. Gharpure, Dandela Anuradha, Jonnalagadda V. K. Prasad and Pidugu Srinivasa Rao
Article first published online: 26 NOV 2014 | DOI: 10.1002/ejoc.201403294
A simple and efficient, Lewis acid catalysed reductive etherification strategy for the stereoselective synthesis of cis-2,6-disubstituted morpholines and 1,4-oxathianes starting from readily available 1,5-diketones has been developed. The strategy is used in the total synthesis of morpholine-based natural product (±)-chelonin A and a formal total synthesis of (±)-chelonin C.
Lorenz M. Urner, Michael Sekita, Nils Trapp, W. Bernd Schweizer, Michael Wörle, Jean-Paul Gisselbrecht, Corinne Boudon, Dirk M. Guldi and François Diederich
Article first published online: 12 NOV 2014 | DOI: 10.1002/ejoc.201403252
The modular synthesis and characterization of a series of rigid ZnII porphyrin conjugates is described. The push–pull chromophores incorporated as electron acceptors feature first reduction potentials ranging from –1.78 to –0.58 V vs. Fc+/Fc, and affect the extent of ZnII porphyrin fluorescence quenching according to their acceptor strength.
Tamam El-Elimat, Mario Figueroa, Huzefa A. Raja, Tyler N. Graf, Steven M. Swanson, Joseph O. Falkinham III, Mansukh C. Wani, Cedric J. Pearce and Nicholas H. Oberlies
Article first published online: 31 OCT 2014 | DOI: 10.1002/ejoc.201402984
Sixteen polyketides, six of them new, were isolated from a fungal culture (Setophoma terrestris). Cytotoxicity assays were used to develop structure–activity relationships amongst the series.
Abhishek Kumar Gupta, Abhimanew Dhir and Chullikkattil P. Pradeep
Article first published online: 26 NOV 2014 | DOI: 10.1002/ejoc.201403073
A series of water-soluble spider-like receptor molecules has been developed by the Schiff-base condensation of tris(hydroxymethyl)aminomethane (TRIS) with 2,6-diformylphenol (dfp) derivatives. The products could be used for selective fluorescent sensing of adenosine-5′-triphosphate (ATP) and cytidine-5′-triphosphate (CTP) in 100 % aqueous media at pH 7.2.
Shota Ooi, Takayuki Tanaka and Atsuhiro Osuka
Article first published online: 14 NOV 2014 | DOI: 10.1002/ejoc.201403217
A rational synthesis of cis-A2B-type corroles through a [2+2] approach has been developed, which allowed the synthesis of six new corroles in moderate yields. These corroles were structurally well-characterized and their optical and electrochemical properties were also studied.
Mothukuri Ganesh Kumar, Varsha J. Thombare, Rupal D. Bhaisare, Anindita Adak and Hosahudya N. Gopi
Article first published online: 25 NOV 2014 | DOI: 10.1002/ejoc.201403237
A facile synthesis of highly symmetrical tetrasubstituted pyrazines through simple aerial oxidation of β-keto γ-esters derived from amino acids and peptides is reported.
Ruokun Feng, Binjie Wang, Yue Liu, Zhanxiang Liu and Yuhong Zhang
Article first published online: 25 NOV 2014 | DOI: 10.1002/ejoc.201403191
A highly effective protocol for the synthesis of C-3-substituted prolines has been developed. Pd-catalyzed C(sp3)–H activation is used for the straightforward functionalization of prolines. The use of an 8-aminoquinolinecarboxamide directing group allows direct arylation, alkenylation, and alkylation at the C-3 position of prolines in moderate to high yields with diverse iodo- or bromo precursors.
Arnaud Chevalier, Kevin Renault, Frédéric Boschetti, Pierre-Yves Renard and Anthony Romieu
Article first published online: 5 NOV 2014 | DOI: 10.1002/ejoc.201403165
Simplicity and diversity! A range of primary and secondary functionalized amines were easily introduced onto a sulfoxanthene dye through simple metal-free SNAr reactions to provide original sulforhodamine fluorophores with promising properties.
Benoît Roubinet, Arnaud Chevalier, Pierre-Yves Renard and Anthony Romieu
Article first published online: 21 NOV 2014 | DOI: 10.1002/ejoc.201403215
A condensation reaction between 7-acetoxy-3-formylcoumarin and various C- and/or N-monosubstituted ortho-phenylendiamine derivatives has led to a new class of 3-(heteroaryl)-7-hydroxycoumarins meeting the requirements for biosensing applications (bioconjugation ability, water solubility, and high “fluorogenic” reactivity).
Guillaume Gros and Jens Hasserodt
Article first published online: 21 NOV 2014 | DOI: 10.1002/ejoc.201402821
A four-step synthetic route to 1,4,7-triazacyclononanes with a 2Ra/Rb N-functionalization pattern is presented. The formation of the macrocycle is greatly facilitated by the use of an organic template. This allows for the atom-economic, multigram syntheses of several substituted derivatives with excellent overall yields in less than five days.
Lauren Myles, Nicholas Gathergood and Stephen J. Connon
Article first published online: 26 NOV 2014 | DOI: 10.1002/ejoc.201402947
A new, organocatalytic approach to the hydrolytic deprotection of dithianes has been developed involving a low-toxicity imidazolium-ion-based catalyst in an aqueous medium.
Sreenu Jennepalli, Katherine A. Hammer, Thomas V. Riley, Stephen G. Pyne and Paul A. Keller
Article first published online: 21 NOV 2014 | DOI: 10.1002/ejoc.201403046
Fullerenyldihydropyrrole peptides were prepared from the coupling of mono and bisfullerenyldihydropyrrolecarboxylic acids with peptides to produce a series of fullerenyl-anchored tetra- and penta-peptides. Their synthesis and characterisation are discussed in this paper.
Eric Buchy, Sabrina Valetti, Simona Mura, Julie Mougin, Claire Troufflard, Patrick Couvreur and Didier Desmaële
Article first published online: 21 NOV 2014 | DOI: 10.1002/ejoc.201403088
New squalene conjugates of antiangiogenic 3-(pyrrolyl)methylidenyl-substituted oxindoles sunitinib and semaxanib were synthesized. Strategies to link squalene to the oxindole nitrogen through a pH-sensitive linker are presented. These squalenoyl prodrugs self-assemble into nanoparticles of about 150 nm in size, and show notable cytotoxicity on the human umbilical vein endothelial cell line
Prasad B. Wakchaure, Sanjay R. Borhade, Anja Sandström and Per I. Arvidsson
Article first published online: 19 NOV 2014 | DOI: 10.1002/ejoc.201403148
N-(α,β-Unsaturated acyl) sulfonimidamides have been prepared through a Pd-catalyzed carbonylation protocol, employing sulfonimidamide nucleophiles, CO gas released ex situ, and vinyl/aryl halides and triflates as reagents. The obtained products undergo facile thermolytic Boc deprotection in DMSO, thereby offering convenient access to deprotected analogues.
Katrin Belger and Norbert Krause
Article first published online: 12 NOV 2014 | DOI: 10.1002/ejoc.201403153
The total synthesis of water-soluble ammonium-salt-tagged NHC–gold complexes is described, as well as their application in aqueous media and their recyclability.
Ismail Abdelshafy Abdelhamid and Holger Butenschön
Article first published online: 5 NOV 2014 | DOI: 10.1002/ejoc.201403247
A bidirectional sequence of electrocyclic ring opening, [4+2] cycloaddition, methanol elimination, and dehydrogenation allows the formation of benzo[1,2-f:4,5-f′]diisoindole-1,3,7,9-tetraones from benzo[1,2:4,5]dicyclobutenes.
Janire Lamariano-Merketegi, Adriana Lorente, Alejandro Gil, Fernando Albericio and Mercedes Álvarez
Article first published online: 17 NOV 2014 | DOI: 10.1002/ejoc.201402987
A chelation-controlled addition, a carboalumination, and a Nozaki–Hiyama–Kishi (NHK) reaction were used to study the stereoselective addition of vinylmetallic reagents to enantiopure trisubstituted 2-formyl-tetrahydrofuran compounds. The optimal conditions for the carboalumination and NHK reactions provided satisfactory yields and diastereoselectivities.
Wolfgang Brenner and Norbert Jux
Article first published online: 25 NOV 2014 | DOI: 10.1002/ejoc.201403067
A fused porphycene is generated through a shortened synthetic route. This molecule will serve as a starting point for the synthesis of larger fused porphycenes.