SYNFORM

SYNFORM is available as part of the online editions of SYNTHESIS, SYNLETT and SYNFACTS through Thieme E-Journals. This supplementary feature is available free of charge. SYNFORM presents people, trends, and views in synthetic organic chemistry with direct links to all quoted original papers. To view or download issues of SYNFORM, please click here.

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As of August 2013 SYNFORM is only available on our Thieme E-Journal Platform.

 

 

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Dear Readers,

 

This issue of SYNFORM features three SYNSTORIES from three different continents. The first one comes from India and describes the very handy, efficient and stereoselective nitration of olefins developed by Professor Maiti, which represents a very attractive alternative to the well-known Henry nitroaldol reaction. The second SYNSTORY comes from the USA and reports on the use of diaziridinone as an oxidant for transforming alcohols into ketones and aldehydes, according to the methodology developed by Professor Shi, which is an interesting alternative to the widely used Swern reaction. The third SYNSTORY comes from Spain and guides us through the new protocol developed by Professor Albericio for the selective construction of disulfide bridges from cysteine-rich peptides on resin, which is an extremely valuable addition to the existing methods for the synthesis of specifically folded peptides. The issue is completed by a Young Career Focus article coming again from Europe, and specifically from the UK, where Dr. O'Donoghue is developing her research which is focused on catalysis at the interface of organic and biological chemistry.

 

Enjoy your reading!

 

Matteo Zanda
Editor of SYNFORM

 

 

 

Posted By: Matteo Zanda on Jul 01, 2013 12:04PM Add Comment

Nitroolefins are invaluable building blocks in modern synthetic chemistry. They are used in a number of carbon–carbon bond-forming reactions including Michael, cycloaddition and Morita–Baylis–Hillman reactions. Conventional synthesis of nitroolefins relies upon a two-step sequence involving a base-mediated Henry reaction between nitromethane and a carbonyl compound, and subsequent dehydration of the intermediate β-nitro alcohol. However, nitration of an olefin, which can be seen as a formal replacement of an alkene hydrogen with a nitro group, is a synthetic approach that presents some potential advantages for synthesizing nitroolefins. In this regard, a number of methods for nitration of olefins have been developed using various metal-based and gaseous nitrating agents. Unfortunately, despite significant recent improvements and advances of this methodology, formation of an undesired mixture of E/Z-isomers, use of harsh reaction conditions and limitations in substrate scope are common traits in the previous protocols.

Recently, the research group of Professor Debabrata Maiti at the Indian Institute of Technology Bombay (Mumbai, India) has been exploring an ipso-nitration of arylboronic acids involving nitro radicals generated from shelf-stable metal nitrates. ...

 

To read more please download SYNFORM 2013/07 online, free of charge.

Posted By: Matteo Zanda on Jul 01, 2013 12:03PM Add Comment

The oxidation of alcohols to aldehydes or ketones is one of the most commonly employed chemical transformations in organic synthesis. While numerous oxidation methods have been developed, only a few of them are used routinely. The development of new and efficient oxidation processes with safe reagents under mild conditions is still highly desirable and valuable. Recently, Professor Yian Shi and co-workers at Colorado State University (Fort Collins, USA) reported a novel and efficient CuBr-catalyzed oxidation of alcohols using di-tert-butyldiaziridinone. ...

 

To read more please download SYNFORM 2013/07 online, free of charge.

Posted By: Matteo Zanda on Jul 01, 2013 12:02PM Add Comment | View Comments [1]

Cysteine-rich peptides such as conotoxins have a number of biological functions and a wide range of biological activities that depend to a great extent on the presence of topologically defined pairs of disulfide bonds that contribute strongly to the conformational stability and three-dimensional folding of these peptides. For many years, the objective of Professor Fernando Albericio’s group at the University of Barcelona (Spain) has been the creation of novel tools for the formation of disulfides in peptide synthesis. The current repertoire of both Cys-protecting groups and disulfide-forming reagents are incomplete due to the lack of convenient, mild, and simple protocols. ...

 

To read more please download SYNFORM 2013/07 online, free of charge.

Posted By: Matteo Zanda on Jul 01, 2013 12:01PM Add Comment

Background and Purpose: SYNFORM will from time to time meet young up-and-coming researchers who are performing exceptionally well in the arena of organic chemistry and related fields of research, in order to introduce them to the readership. This SYNSTORY with a Young Career Focus presents Dr. AnnMarie O’Donoghue, Durham University, UK. ...

 

To read more please download SYNFORM 2013/07 online, free of charge.

Posted By: Matteo Zanda on Jul 01, 2013 12:00PM Add Comment

 

Dear Readers,

 

I am writing this editorial in the bar of a rather posh Hotel in Brussels, while enjoying a very good Belgian beer. What am I doing here? Well... you could easily guess... it’s European Commission stuff. More precisely, EU project evaluations. I can’t say more; it’s confidential, you know. I can easily see what you are thinking now: I am here in this posh Hotel because I am taking advantage of European taxpayers’ money. Well, that’s not true... we get a lump sum from the European Commission, and we can save on that or rather waste it all in a posh Hotel like this one. I like this place, I see it as a reward and I try to make the most of these situations, which don’t happen every day. It’s a perfect situation for thinking and writing. Writing this editorial for example, right now there is classical music in the background – honestly I would prefer Michael Bublé in this situation... but that’s still OK. So, let’s try to remember why I am writing these things.... oh yes, of course! It’s SYNFORM! And it’s a great issue of SYNFORM, by the way! The first SYNSTORY is about a new powerful method for achieving alkylation of pyridines on C-4, developed by Professor M. Kanai (Japan). Next, we have the conceptually innovative synthesis of xanthones and fluorenones proposed by Professor F. Glorius (Germany). The third SYNSTORY leads us into the intriguing world of pyridynes (not pyridines!) that was recently explored by Professor N. K. Garg (USA). Finally, we jump into the hot-area of C(sp3)–H bond functionalizations under the expert guidance of Professor J.-Q. Yu (USA). It’s a heavy load of great chemistry!

 

Enjoy your reading!

 

Matteo Zanda
Editor of SYNFORM

P.S. And I am still enjoying my Belgian beer ;-)

 

 

 

Posted By: Matteo Zanda on Jun 01, 2013 12:04PM Add Comment

The nucleophilic addition of organometallic reagents to electrophiles is a fundamental C–C bond-forming reaction in organic synthesis. The generation of nucleophilic organometallic reagents, however, generally requires stoichiometric amounts of strong bases and/or reducing metals, such as Mg and Li, and stoichiometric salt waste is therefore inevitably produced. Thus, the development of atom-economical processes, involving the catalytic generation of nucleophilic organometallic species without any stoichiometric amounts of activating reagents, is highly desirable. The group of Professor Motomu Kanai at The University of Tokyo (Japan) is trying to develop new methods to catalytically generate nucleophilic active species in situ under first-row transition-metal catalysis ...

 

To read more please download SYNFORM 2013/06 online, free of charge.

Posted By: Matteo Zanda on Jun 01, 2013 12:03PM Add Comment

Fluorenones and xanthones are core motifs of many natural and biologically active compounds, as well as organic light-emitting materials. Existing synthetic routes to these compounds, such as Friedel–Crafts-type ring closures or the oxidation of fluorenes, are usually limited to electron-rich arenes or require multiple-step synthesis.
Recently, Professor Frank Glorius and Dr. Zhuangzhi Shi of the Organic Chemistry Institute at the Universität Münster (Germany) developed a novel and efficient route for the synthesis of fluorenones via direct intramolecular dehydrogenative arylation of aldehydes. The Glorius group has focused its research activity on the catalytic selective functionalization of aldehyde C–H bonds to construct ketones via transition-metal complexes and N-heterocyclic carbene catalysts. ...

 

To read more please download SYNFORM 2013/06 online, free of charge.

Posted By: Matteo Zanda on Jun 01, 2013 12:02PM Add Comment

Arynes are fascinating, yet synthetically useful and highly reactive intermediates, which occupy a pivotal role in organic synthesis. Although benzyne is probably the best known and most used aryne intermediate, a number of heterocyclic arynes have been described and successfully used in a wide range of synthetic methods. The first aryne proposed (over 100 years ago) in fact was a heterocyclic aryne, which was obtained from 3-bromobenzofuran (Ber. Dtsch. Chem. Ges. 1902, 35, 1633). However, arguably the synthetic potential of such compounds has not been unlocked until recently.
For some time, the research laboratory of Professor Neil Garg at the University of California, Los Angeles (UCLA, USA) has been interested in the chemistry of heterocyclic arynes. Professor Garg said: “In earlier efforts, we studied ‘indolynes’ as a means to prepare substituted indole derivatives. This work led to the synthesis of alkaloids, such as indolactam V and several welwitindolinone natural products.” Importantly, collaborative studies with Professor Ken Houk at UCLA also led to the establishment of the aryne distortion model. This model allows one to make reliable predictions about regioselectivity in reactions of unsymmetrical arynes, including hetarynes. ...

 

To read more please download SYNFORM 2013/06 online, free of charge.

Posted By: Matteo Zanda on Jun 01, 2013 12:01PM Add Comment

α-Propargyl carboxylic acids and their derivatives are extremely important and valuable molecules having a number of applications as drugs, key building blocks for the synthesis of complex natural and bioactive compounds, tools for biomedical research, and innovative bio-materials. In fact, the propargylic function imparts increased reactivity and offers the possibility of introducing further bespoke functionalities for the fine-tuning of their biological activity, as well as acting as a bioconjugation site. An attractive strategy for the synthesis of α-propargyl carboxylic acid derivatives would be the conversion of a C–H bond positioned β to a carboxamide function into an alkyne by formation of a new C–C bond with an activated alkyne derivative. Unfortunately, this potentially versatile methodology has remained elusive owing to the apparent lack of reactivity of such an inactivated C–H bond and the absence of suitable catalytic systems. Recently, the group of Professor Jin-Quan Yu from the Scripps Research Institute (La Jolla, CA, USA) developed a methodology for achieving such a striking transformation, based on the use of Pd(0) catalysts with N-heterocyclic carbene (NHC) or phosphine (PR3) ligands. ...

 

To read more please download SYNFORM 2013/06 online, free of charge.

Posted By: Matteo Zanda on Jun 01, 2013 12:00PM Add Comment