Archive for the ‘Reviews’ Category

Issue 31 online now, complete with mutant lipases & cyclic di-oxoguanidines

Organic & Biomolecular Chemistry issue 31, it’s here and waiting to be read!

Secondary alcohols having bulky substituents on both sides of the hydroxy group are inherently poor substrates for most lipases. In a paper by Tadashi Ema et al., highlighted on this week’s front cover of OBC (right), the detailed rational design and creation of mutant lipases that display remarkably enhanced catalytic activity and enantioselectivity for poor substrates bearing bulky substituents on both sides of the hydroxy group is presented.

Redesign of enzyme for improving catalytic activity and enantioselectivity toward poor substrates: manipulation of the transition state
Tadashi Ema, Yasuko Nakano, Daiki Yoshida, Shusuke Kamata and Takashi Sakai
DOI: 10.1039/C2OB25614B

The inside front cover (left) highlights the Communication of Wen-Xiong Zhang and Zhenfeng Xi et al., presenting the first metal-free one-pot sequential coupling of various amines, carbodiimides and acyl dichlorides, providing a simple and straightforward path to cyclic di-oxoguanidines via an unexpected 2,2-dichloroimidazolidindione intermediate.

Metal-free synthesis of cyclic di-oxoguanidines via one-pot sequential transformation of amines, carbodiimides and acyl dichlorides
Fei Zhao, Yang Wang, Wen-Xiong Zhang and Zhenfeng Xi
DOI: 10.1039/C2OB25799H

Both of these featured articles are FREE to access for the next 6 weeks, why not have a read and let us know your thoughts by commenting below.

 

Also in this issue:

Emerging Area
Transition metal-catalyzed fluorination of multi carbon–carbon bonds: new strategies for fluorinated heterocycles
Guosheng Liu
DOI: 10.1039/C2OB25702E

Perspective
Discovery, application and protein engineering of Baeyer–Villiger monooxygenases for organic synthesis
Kathleen Balke, Maria Kadow, Hendrik Mallin, Stefan Saß and Uwe T. Bornscheuer
DOI: 10.1039/C2OB25704A

View the complete issue online now……

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View OBC issue 28 today – it’s out now!

The front cover of this issue of OBC highlights the work of Tirumala G. Varadarajua and Jih Ru Hwu, demonstrating an efficient and convergent route for the synthesis of the natural product (+)-lithospermic acid, developing two different synthetic routes for the diastereoselective synthesis of the trans-dihydrobenzo[b]furan segment of lithospermic acid.

Synthesis of anti-HIV lithospermic acid by two diverse strategies
Tirumala G. Varadaraju and Jih Ru Hwu
DOI: 10.1039/C2OB25575H

The Communication highlighted on the inside cover of this issue comes from Pandi Muthupandi and Govindasamy Sekar, Indian Institute of Technology Madras, and presents the synthesis of an unusual dinuclear chiral iron complex that was used to asymmetrically hydrophosphorylate aldehydes to synthesis optically active α-hydroxy phosphonates.

Synthesis of an unusual dinuclear chiral iron complex and its application in asymmetric hydrophosphorylation of aldehydes
Pandi Muthupandi and Govindasamy Sekar
DOI: 10.1039/C2OB25810B


Other great content in this week’s issue of OBC includes:

Emerging Area
Chiral quaternary phosphonium salts: a new class of organocatalysts
Dieter Enders and Thanh Vinh Nguyen
DOI: 10.1039/C2OB25823D

Perspective
Self-assembly driven by an aromatic primary amide motif
Myungeun Seo, Jeyoung Park and Sang Youl Kim
DOI: 10.1039/C2OB25117E

Read the FUL ISSUE today!

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OBC issue 27, featuring continuous-flow synthesis and core-modified porphyrins

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….

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A glimpse of OBC issue 26 and its metallic organophosphates and rubesanolide covers

The latest issue of OBC is now available to access, and here’s a quick peek…

Steaming its way on to the front cover is this image (right) from Alejandro Parra & José Alemán et al. Their perspective gives the reader a general overview of some of the most relevant topics in the applications of chiral metallic organophosphates, and includes a selection of the most outstanding uses of these catalysts.

Metallic organophosphates as catalysts in asymmetric synthesis: a return journey
Alejandro Parra, Silvia Reboredo, Ana M. Martín Castro and José Alemán
Org. Biomol. Chem., 2012, 10, 5001–5020

And coming into bloom on the inside cover is this image (left) highlighting the work Hongjie Zhang et al. describing the isolation and structure elucidation of 3 novel abietane diterpenoids, rubesanolides C–E (1–3) from the leaves of the medicinal plant Isodon rubescens

Rubesanolides C–E: abietane diterpenoids isolated from Isodon rubescens and evaluation of their anti-biofilm activity
Juan Zou, Lutai Pan, Qiji Li, Jianxin Pu, Ping Yao, Min Zhu, Jeffrey A. Banas, Hongjie Zhang and Handong Sun
Org. Biomol. Chem., 2012, 10, 5039–5044

Read both for FREE for the next 6 weeks!


As well as many excellent papers, there is also this perspective by Ramakrishna Edupuganti and Franklin A. Davis on the synthesis and applications of masked oxo-sulfinamides in asymmetric synthesis.

Find the complete OBC issue 26 here…

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OBC issue 25 now online: featuring Yamada–Otani condensation & organocatalytic dendrimers

Welcome, dear reader, to issue 25 of OBC!

The front cover of this week’s issue highlights the work of Rich G. Carter, Oregon State University, and colleagues. In this paper Carter et al. present the development of a proline sulphonamide-catalysed method that facilitates the annulation of α-aryl, α-alkyl-disubstituted aldehydes with acyclic enones to produce highly functionalized cyclohexenones with very good degrees of diastereoselectivity and enantioselectivity.

Proline sulphonamide-catalysed Yamada–Otani condensation: reaction development, substrate scope and scaffold reactivity
Hua Yang, Somdev Banerjee and Rich G. Carter
DOI: 10.1039/C2OB25400J

The inside cover highlights the review of Brian Rasmussen and Jørn Bolstad Christensen that looks at the growing field of organocatalysis with dendrimers. This review outlines advances made in this area of organocatalysis and covers both interior- and surface-based examples, the catalysis of reactions ranging from functional group interconversion and C–C bond forming reactions to enzyme mimicking processes.

Organocatalytic dendrimers
Brian Rasmussen and Jørn Bolstad Christensen
DOI: 10.1039/C2OB25317H


Also featuring in this issue are several examples of our Organocatalysis web themed issue. Including the front cover article these are: 

Asymmetric Michael addition of boronic acids to a γ-hydroxy-α,β-unsaturated aldehyde catalyzed by resin-supported peptide
DOI: 10.1039/C2OB25431J, Communication

Catalyst development for organocatalytic hydrosilylation of aromatic ketones and ketimines
DOI: 10.1039/C2OB25472G, Paper

Polystyrene-supported TBD catalyzed ring-opening of N-tosylaziridines with silylated
DOI: 10.1039/C2OB25435B, Paper

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Review: Modulation of the antioxidant activity of phenols by non-covalent interactions

This review by Riccardo Amorati and Luca Valgimigli, University of Bologna, is featured in issue 21 of OBC, which can now be found online.

In this Perspective Amorati and Valgimigli summarize some recent results obtained with simplified models, which can aid in understanding the effects of non-covalent interactions, i.e.  intra- and inter-molecular H-bonds, on the radical chemistry of natural phenolic and polyphenolic antioxidants.

Areas of discussion include:

Intramolecular hydrogen bonds:

Reactive OH groups as H-bond donors

Reactive OH groups as H-bond acceptor

Remote H-bond effect

Intermolecular hydrogen bonds

Reactive OH groups as H-bond donors: the “classical” kinetic solvent effect (KSE)

The remote kinetic solvent effect (RKSE)

Other solvent effects

Read this well received review today!

Modulation of the antioxidant activity of phenols by non-covalent interactions
Riccardo Amorati and Luca Valgimigli
Org. Biomol. Chem., 2012, 10, 4147-4158
DOI: 10.1039/C2OB25174D

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Issue 19 online with quantum mechanical tunnelling & 2-substituted 3-bromopyrrolidines on the covers

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!

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Chiral recognition of carbon nanoforms & 3-alkyl enol mimic inhibitors on the cover of OBC issue 18

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

                            Both of these articles are free to access for 6 weeks so get your hands on them today!                              

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

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Promiscuous enantioselective lactamase activity on the cover of OBC issue 17

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:

 A review:

 Making expensive dirhodium(II) catalysts cheaper: Rh(II) recycling methods
Nuno R. Candeias, Carlos A. M. Afonso and Pedro M. P. Gois
Org. Biomol. Chem., 2012, 10, 3357-3378
DOI: 10.1039/C2OB06731E

A HOT article:

Copper-mediated domino synthesis of pyrimido[4,5-b]carbazolones via Ullmann N-arylation and aerobic oxidative C–H amidation
Devanga K. Sreenivas, Nagarajan Ramkumar and Rajagopal Nagarajan
Org. Biomol. Chem., 2012, 10, 3417-3423
DOI: 10.1039/C2OB07179G

 View the entire issue HERE

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OBC issue 16 has landed!

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….

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