Organic & Biomolecular Chemistry Blog

The front cover (right) of this issue of Organic & Biomolecular Chemistry features the work Takashi Takahashi and colleagues at Tokyo Institute of Technology. Takahashi et al. present a two-stage continuous-flow synthesis of activated vitamin D₃, the first application of a micro-flow system to this synthesis. The authors claim that the synthesis should be easy to scale up and that it required no purification of intermediates or high dilution conditions, and so reducing wastage.

Continuous-flow synthesis of activated vitamin D₃ and its analogues
Shinichiro Fuse, Yuto Mifune, Nobutake Tanabe and Takashi Takahashi

The inside cover (left) highlights work by Chihiro Maeda and Naoki Yoshioka, Keio University, on the synthesis of peripherally ethynylated carbazole-based core-modified porphyrins. Maeda and Keio make use of a series of metal-catalyzed coupling and annulation reactions to produce the porphyrins whose π-conjugated networks are shown to effectively delocalise over the entire macrocycle.

Peripherally ethynylated carbazole-based core-modified porphyrins
Chihiro Maeda and Naoki Yoshioka

As always these cover articles are free to access for 6 weeks.

Also in this issue is this HOT communication:

First total synthesis of the biscarbazole alkaloid oxydimurrayafoline
Carsten Börger, Micha P. Krahl, Margit Gruner, Olga Kataeva and Hans-Joachim Knölker

And, the perspective ‘Strategies for the enantioselective synthesis of spirooxindoles’

Find the complete issue HERE….

On the front cover is this HOT Emerging Areaarticle from Peter R. Schreiner and co-workers (Justus-Liebig University, Germany) who discuss quantum mechanical tunnelling and provide an overview of the importance of tunnelling in organic chemical reactions.
Discussion includes:

• a brief history of tunnelling
• hydrogen tunnelling
• carbon tunnelling
• heteroatom tunnelling

Tunnelling control of chemical reactions – the organic chemist’s perspective
David Ley, Dennis Gerbig and Peter R. Schreiner
Org. Biomol. Chem., 2012, 10, 3781-3790
DOI: 10.1039/C2OB07170C

On the inside front cover is this Communication, from Ying-Yeung Yeung and colleagues at National University of Singapore, where a facile and highly enantioselective route to 2-substituted 3-bromopyrrolidines is presented. The authors demonstrate how these can be reached via the bromo-aminocyclisation of 1,2-disubstituted olefinic amides using amino-thiocarbamates as a catalyst. This is also part of our growing Organocatalysis web collection.

A highly enantioselective approach towards 2-substituted 3-bromopyrrolidines
Jie Chen, Ling Zhou and Ying-Yeung Yeung
Org. Biomol. Chem., 2012, 10, 3808-3811
DOI: 10.1039/C2OB25327E

Both of these cover articles will be free to access for the next 6 weeks.

Also in this issue:

A perspectiveby Alessandro Massi and Daniele Nanni:
Thiol–yne coupling: revisiting old concepts as a breakthrough for up-to-date applications

And 2 HOT articles that are still free to access for another 3 weeks

Diastereoselective alkylation reactions of 1-methylcyclohexa-2,5-diene-1-carboxylic acid
Mark C. Elliott et al.

Glycosylated diazeniumdiolate-based oleanolic acid derivatives: synthesis, in vitro and in vivo biological evaluation as anti-human hepatocellular carcinoma agents
Yihua Zhang et al.

View the entire issue HERE, it’s full of lots of great content!

We are pleased to present to you OBC issue 18, 2012

Emilio M. Pérez and Nazario Martín present an Emerging area article providing an overview of some of the few successful examples of chiral recognition of carbon nanoforms, highlighting their common features with the aim of helping to develop general trends for the design of new generations of hosts.

Chiral recognition of carbon nanoforms
Emilio M. Pérez and Nazario Martín
Org. Biomol. Chem., 2012, 10, 3577–3583
DOI: 10.1039/C2OB07159B

The inside front cover illustrates work by Concepción González-Bello and co-workers at Universidad de Santiago de Compostela and University of Newcastle upon Tyne, who synthesised several 3-alkylaryl mimics of the enol intermediate in the the reversible dehydration reaction of 3-dehydroquinic acid, which is catalysed by type II dehydroquinase, to investigate the effect on the inhibition potency of replacing the oxygen atom in the side chain by a carbon atom.

Synthesis of 3-alkyl enol mimics inhibitors of type II dehydroquinase: factors influencing their inhibition potency
Beatriz Blanco, Antía Sedes, Antonio Peón, Heather Lamb, Alastair R. Hawkins, Luis Castedo and Concepción González-Bello
Org. Biomol. Chem., 2012, 10, 3662–3676
DOI: 10.1039/C2OB07081B

Also in this issue:

A perspective by María Paz Muñoz covering the progress in transition metal-catalysed intermolecular reaction of allenes with oxygen nucleophiles, analysing the intermolecular metal-catalysed reaction of allenes using palladium, iridium, rhodium, ruthenium, gold and platinum, in the presence of alcohols, water or carboxylic acids, and the mechanistic implications of these processes depending on the metal used.

Transition metal-catalysed intermolecular reaction of allenes with oxygen nucleophiles: a perspective María Paz Muñoz
Org. Biomol. Chem., 2012,
DOI: 10.1039/C2OB07128B
 
The HOT article :
A convenient biomimetic synthesis of optically active putative neurotoxic metabolites of MDMA (“ecstasy”) from R-(−)- and S-(+)-N-methyl-α-methyldopamine precursors
Claire-Marie Martinez, Anne Neudörffer and Martine Largeron
DOI: 10.1039/C2OB25245G

This week’s OBC cover highlights the work of Aurelio Hidalgoand co-workers at the Center for Molecular Biology, whose paper describes the promiscuous enantioselective (−)-γ-lactamase activity in Pseudomonas fluorescensesterase I. In the paper Aurelio Hidalgoet al. show how the introduction of a mutation to the wild esterase improved the reaction turnover without affecting the enantioselectivity. Read the paper to find out more…..

This paper is FREE to access for the next 6 weeks, so why not take a look at it.

Promiscuous enantioselective (−)-γ-lactamase activity in the Pseudomonas fluorescensesterase I
Leticia L. Torres, Anna Schließmann, Marlen Schmidt, Noella Silva-Martin, Juan A. Hermoso, José Berenguer, Uwe T. Bornscheuer and Aurelio Hidalgo
Org. Biomol. Chem., 2012, 10, 3388-3392
DOI: 10.1039/C2OB06887G

Also in this issue:

 View the entire issue HERE

The outside front cover of this week’s OBC is a communication from Barbara Zajcand colleagues at The City College and The City University of New York presenting a mild and efficient synthesis of 1-aryl-1-fluoroethenes from benzothiazolyl (aryl)fluoromethyl sulfones and paraformaldehyde, under DBU- or Cs₂CO₃-mediated conditions at room temperature.

Expedient synthesis of α-substituted fluoroethenes
Samir K. Mandal, Arun K. Ghosh, Rakesh Kumar and Barbara Zajc
Org. Biomol. Chem., 2012, 10, 3164–3167
DOI: 10.1039/C2OB07031F

The inside front cover is work from Keisuke Kato et al. at Toho University on the cyclization–carbonylation–cyclization coupling reaction of γ-propynyl-1,3-diketones catalysed by palladium(II)-bisoxazoline complexes to give symmetrical ketones bearing two oxabicyclic groups in moderate to excellent yields.

Cyclization–carbonylation–cyclization coupling reaction of γ-propynyl-1,3-diketones with palladium(II)-bisoxazoline catalyst
Taichi Kusakabe, Yasuko Kawai, Rong Shen, Tomoyuki Mochida and Keisuke Kato
Org. Biomol. Chem., 2012, 10, 3192–3194
DOI: 10.1039/C2OB07016B

Also in this issue:

Review:

Recent advances and applications of iridium-catalysed asymmetric allylic substitution by Paolo Tosatti and co-workers

Hot articles:

Electrophilicity of α-oxo gold carbene intermediates: halogen abstractions from halogenated solvents leading to the formation of chloro/bromomethyl ketones
Weimin He, Longyong Xie, Yingying Xu, Jiannan Xiang and Liming Zhang

Highly enantioselective [4 + 2] cycloadditions of allenoates and dual activated olefins catalyzed by N-acyl aminophosphines
Hua Xiao, Zhuo Chai, Dongdong Cao, Hongyu Wang, Jinghao Chen and Gang Zhao

Enantioselective synthesis of fluorene derivatives by chiral N-triflyl phosphoramide catalyzed double Friedel–Crafts alkylation reaction
Shou-Guo Wang, Long Han, Mi Zeng,  Feng-Lai Sun, Wei Zhang and Shu-Li You

Hydrogen tunnelling influences the isomerisation of some small radicals of interstellar importance. A theoretical investigation
Tianfang Wang and John H. Bowie

See the rest HERE….