SYNFORM is available as part of the online editions of SYNTHESIS, SYNLETT and SYNFACTS through Thieme eJournals. 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.
This issue of SYNFORM is dominated by Asian chemistry and chemists, which is not at all surprising given the impressive development of countries like P. R. of China, India, Singapore, South Korea and others which are now competing with Japan on the continental scale and synergistically acting with Japan in establishing Asia as the new giant in the global research arena. In the first SYNSTORY Professor I. Ryu (Japan) guides us through his recent radical process based on the addition of alkyl halides to an under-utilized, at least in radical chemistry, one-carbon building block such as formaldehyde. The second SYNSTORY brings us to the P. R. of China where Professor H. Huang has recently established a new world record in the simultaneous formation of six new contiguous stereocenters in one molecule, a highly functionalized cyclohexane, by means of a single synthetic step. Last but not least, the Editorial Advisory Board profile features Professor K. Suzuki (Japan).
SYNFORM will from time to time portrait SYNTHESIS/SYNLETT Advisory Board members who answer several questions regarding their research interests and revealing their impressions and views on the developments in organic chemistry as a general research field.
The stereoselective installation of contiguous multiple stereocenters through catalytic reactions from simple starting materials represents one of the most important subjects in synthetic organic chemistry, since structural frameworks featuring multiple contiguous stereocenters are widespread in natural and unnatural products that exhibit potent biological activity. The number of possible stereoisomers increases exponentially with the number of stereocenters; therefore, the highly stereoselective synthesis of chiral molecules with contiguous multiple stereocenters from simple starting materials in one step represents a challenging endeavor. Asymmetric domino processes that generate more than one chemical bond concomitantly with the creation of multiple stereocenters in a one-pot fashion has emerged as a promising way to synthesize these structural units. Recently, the group of Professor Hanmin Huang from the Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences (P. R. of China) reported a new methodology for the generation of highly functionalized cyclohexane carboxylates with six stereogenic centers (up to 98% ee, dr > 20:1) via transition-metal-catalyzed asymmetric formal [2+2+2] annulation between α-keto esters and nitroalkenes.
To read more please download SYNFORM 2012/05 online, free of charge.
Whereas carbon monoxide, isonitriles, and substituted oxime ethers have found wide applications in radical-mediated multi-component reactions as viable C1 synthons, the utilization of formaldehyde has been only marginally explored. This is in sharp contrast with the fact that formaldehyde is a quite common reagent in carbanion chemistry, and has been successfully used for one-carbon homologation reactions.
Recently, however, the group of Professor Ilhyong Ryu from Osaka Prefecture University (Japan) developed an efficient radical process for the hydroxymethylation of haloalkanes, in which formaldehyde is used as C1 radical synthon.
To read more please download SYNFORM 2012/05 online, free of charge.
Recently I was talking to a colleague about professional social networks, and he was of the opinion that some of them are very useful not just to keep in touch with colleagues, friends and former students around the world, but also for acquiring every sort of information useful at professional level, from job openings to recent trends in research (including the attendance of webinars) and even some kind of gossip. Personally, I am not a heavy user of these social networks (actually I am not even on Facebook...) and I think I am spending already too much time online answering to e-mails and retrieving information on the web. However, yesterday I decided to have a closer look at one of these websites, where I have been registered for the last three years without even updating my profile, and I had the impression that the whole world was there, I could even find some of my old school mates! After a couple of hours, I had to admit to myself that professional social networks are indeed a very useful tool, provided one does not become addicted. So, I decided I will try to get more involved and make a better use of this tool although I am strongly determined not to become a slave! Will I succeed? I’ll let you know... The other decision I’ve made is that I will continue to live without Facebook. At least for the moment... As you know, there is another tool for staying in touch with the community of organic chemists and receive exclusive information on the most exciting breakthroughs and discoveries: it’s SYNFORM! This issue, for example, explains how Professor N. Zheng (USA) was able to develop his amazing photocatalyzed cycloaddition between cyclopropylamines and olefins. In the second SYNSTORY Professor K. Itami takes us through his superb Ni-catalyzed crosscoupling reaction producing heterobiaryls from azoles and phenols. Last but not least, Professor S. Canesi (Canada) is the protagonist of the Young Career Focus.
There is an upsurge of interest in using visible light for promoting the formation of carbon–carbon bonds. This is motivated by both environmental and economic reasons, given the abundance and widespread availability of solar energy. However, photoredox catalysts such as ruthenium or iridium polypyridyl complexes are normally needed to achieve efficient visible-light-promoted synthetic processes. In this process, Ru(I) and Ir(II) are oxidatively photo-excited to Ru(II) and Ir(III), respectively, and amines are used as sacrificial electron donors to reduce these oxidized cations back to the original oxidation state. Recently, the group of Professor Nan Zheng from the University of Arkansas (USA) designed a new, more atom-economical process employing amines as both the substrates and the sacrificial donors.
To read more please download SYNFORM 2012/04 online, free of charge.
Biaryls and heterobiaryls are ubiquitous motifs in pharmaceuticals, natural products, and organic materials alike, and therefore the construction of these scaffolds has been a topic of great importance in chemistry. As widely announced within the chemical community and beyond, research in ‘palladiumcatalyzed cross-coupling reactions’ was awarded the Nobel Prize in Chemistry in 2010, highlighting its significance. Since cross-coupling reactions are undoubtedly among the most reliable methods for constructing biaryls and heterobiaryls, many chemists have contributed to their improvement over the last few decades. However, these reactions generally require the use of: (i) metalated arenes/heteroarenes as aryl nucleophiles, which are synthesized from simpler arenes/heteroarenes in multi-step reactions; (ii) halogenated arene/heteroarenes as aryl electrophiles; and (iii) expensive palladium as catalyst. “The next phase of research in cross-coupling chemistry will have to solve the above problems in order to develop more efficient processes, and there are currently three ways in which cross-coupling chemistry can ‘evolve’, which are summarized in Scheme 2,” said Professor Kenichiro Itami, an expert in this area of chemistry from Nagoya University (Japan).
To read more please download SYNFORM 2012/04 online, free of charge.
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 Professor Sylvain Canesi, Université du Québec à Montréal, Canada.
To read more please download SYNFORM 2012/04 online, free of charge.
Last week I was preparing a conference call with an AstraZeneca research center in the UK, when I suddenly got a “cancellation” message, followed by an email stating that “Following on from today’s announcements within AstraZeneca, we have decided to postpone the meeting today to allow everyone here to fully understand the implications”. Surprised, I checked the News online and I immediately found the headline: “AstraZeneca to cut 7,300 jobs”. Clearly I was witnessing live another major blow in the Big Pharma arena. This sad event follows previous payroll-cuttings from Pfizer, Novartis, Sanofi, Teva, Takeda Pharmaceuticals, and the list could continue. There are many reasons for this gloomy situation, generic competition is probably the most important one. But fortunately there was some good news too according to related online articles, because other smaller drug-maker companies seem to be doing well and the Wall Street Journal recently reported that industry experts are foreseeing a turnaround in 2013.On the other hand, Research & Development is undergoing a deep restructuring and re shaping virtually in every big pharmaceutical company, and this may lead to major opportunities for those who will be able to understand and adapt themselves to this change of scenario. Hopefully organic chemistry will re-emerge stronger than ever.
This issue of SYNFORM is opened by a SYNSTORY article on a boron-mediated carbon – carbon bond forming process discovered by Professor D. G. Hall (Canada), which is followed by a report on a gold-catalyzed introduction of an acyloxy group on aromatic residues developed by Dr. V. Michelet (France), and concluded by an Advisory Board Focus on Professor U. Koert (Germany). Clearly the global economic crisis is not affecting the quality of the science featured in SYNFORM!
Novel methods to form carbon – carbon bonds in a stereocontrolled manner remain a landmark achievement in synthetic organic chemistry. Palladium-catalyzed cross-coupling reactions are extremely powerful tools to achieve this goal; however, cross-coupling processes involving sp3 carbons are generally much more challenging than those involving sp2 carbons (i.e., aryl and vinyl substrates). Boron compounds are very important in palladium-catalyzed cross-coupling chemistry, as demonstrated in the many outstanding applications of the Nobel Prize winning Suzuki – Miyaura coupling. However, some facets of this powerful methodology are still in need of development, such as stereoselective cross-couplings. Recently, the group of Professor Dennis G. Hall from the University of Alberta (Edmonton, Canada) reported very important progress in the field, describing the first preparation of optically pure 1,1-alkyldiboronyl compounds (gem-diboronic esters) along with their utilization in chemoselective and stereoselective cross-coupling chemistry. The underlying synthetic concept of this work is summarized in Scheme 1.
To read more please download SYNFORM 2012/03 online, free of charge.
