Electrochemical Cascade N ‐Acylation and C–H Halogenation of Azaindoles

Nanomaterials have asserted their position in almost every field due to their wide applicability. While many nanomaterials find direct application in the physical and chemical industry, their applications in pharmacology and medicine require proper modifications to make them biocompatible through a process called biofunctionalization. Biofunctionalization is a fundamental technique for permanent or temporary modification of materials by changing the properties or modification of the surface to have a biologically compatible function. Synthesis and subsequent biofunctionalization of a nanomaterial for a specific biomedical application basically depend on physicochemical and biological properties of nanomaterial. Biofunctionalization can be done using the top-down or bottom-up approach. The top-down approaches such as grinding, ball millings, and heating are the most popular physical processing methods for large scale industrial production of biofunctionalized nanomaterials that are further engineered for biomedical uses. In the bottom-up approach, physical processes like laser ablation, physical vapor deposition, and chemical processes like chemical vapor deposition, self-assembled monolayer formation are involved to make them biocompatible. Functionalization of nanomaterials surfaces implicates liposomes, polymer drug conjugates, dendrimer, polymeric nanoparticle, nucleic acid-based 426nanoparticles, andquantumdots fortargeted drug delivery. To engineer surfaces of these nanoparticles, various biocompatible targeting ligands categorized as organic nanocarriers such as liposomes, dendrimer, polymeric nanoparticle, peptides, aptamers, and inorganic nanoparticles like metal nanoparticles are primarily used. Surface functionalization of nanomaterials is based on the basic principle of noncovalent and covalent interactions. The noncovalent approaches include the adsorption phenomenon in which the targeting ligand is adsorbed on the surface of the nanoparticle through noncovalent forces like the electrostatic force of attraction, hydrophobic interactions, and hydrogen bonding. This chapter intends to delineate the processes and mechanisms involved in the biofunctionalization of nanomaterials and highlight their potential applications in medicine and pharmacology.

Asymmetric Total Synthesis of Phomarol

There is a growing drive in the chemistry community to exploit rapidly growing robotic technologies along with artificial intelligence-based approaches. Applying this to chemistry requires a holistic approach to chemical synthesis design and execution. Here, we outline a universal approach to this problem beginning with an abstract representation of the practice of chemical synthesis that then informs the programming and automation required for its practical realization. Using this foundation to construct closed-loop robotic chemical search engines, we can generate new discoveries that may be verified, optimized, and repeated entirely automatically. These robots can perform chemical reactions and analyses much faster than can be done manually. As such, this leads to a road map whereby molecules can be discovered, optimized, and made on demand from a digital code.

Heterocyclic compounds have shown many important applications in medicine, pesticide and materials.The synthetic method of heterocyclic compounds is one of the focused fields in organic synthesis.Small organic molecules like L-proline and its derivatives are readily commercially available catalyst and have been used in some important organic reactions.The applications of L-proline in catalyzing the synthesis of heterocyclic compounds in recent years are reviewed.Most mentioned synthetic methods have the advantages of mild reaction conditions, easily operation, high yields and environmentally friendly.

Silver N-heterocyclic carbenes: emerging powerful catalysts

Academic–Industrial Partnerships in Drug Discovery and Development

The 1,2,3-triazole scaffolds are an important class of biologically privileged heterocyclic compounds with several key applications in chemistry, biology, medicine, agriculture, and material science. The "postclick" functionalization of 1,2,3-triazoles may emerge as a promising tactic for the construction of molecular architectures of therapeutics and is considered to be a growing area of investigation. This interest extends beyond the regioselective Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) method that involves the trapping of Cu(I)-triazole with suitable precursors. In this Perspective, we highlight the growing impact of postclick strategies in organic synthesis required for the late-stage functionalization of 1,2,3-triazoles with a hope that this emerging concept may provide ample opportunities in modern organic synthesis of notable applications in medicinal chemistry, biology, and materials science.

Aromatic halogenated compounds have been used for over a century as important chemicals or intermediates in organic synthesis. Iodoarenes are valuable intermediates in the synthesis of a wide variety of organic compounds via reactions involving C-C bond formation by transition metals. They have many applications in pharmacology, medicine, and biochemistry. Since iodine is the least reactive halogen towards the electrophilic substitution, direct iodination of aromatic compounds with iodine is difficult. A large diversity of methods for synthesis of aromatic iodides have been reported. Some of the reported procedures need harsh conditions such as HNO3 /H2SO4 , HIO3 or HIO4 /H2SO4 , KMnO4 /H2SO4, CrO3 in acidic solution with I2 , vanadium salts/CF3SO3H at 100 ◦C,9 Pb(OAc)4 /HOAc. NIS/CF3SO3H has also been reported for direct iodination of highly deactivated aromatics. The other reported protocols are: I2 /HgX2 , ICl/Ag2SO4/H2SO4 , NIS/CF3CO2H , I2 /Ag2SO4 , I2 /F-TEDA-BF4 ,NIS/CH3CN , and(CH3)4 NICl2 . Our goal, in undertaking this line of work, was to overcome the limitations and drawbacks of the reported methods, which mentioned above, and also, to develop a high-yielding one-pot synthesis of iodoarenes using a novel combination of reagents. ∗Corresponding author

Microscopic crystals with soft phyllosilicate group of minerals which formed through precipitation of water solution, are called montmorillonite (MMT). It is concentrated and transformed by natural weathering in environment caves and left aluminosilicates which were contained in the bedrock. By the adding water, montmorillonite swells and expanded considerably more than other clays. The amount of expansion is depended on the type of exchangeable cation contained in the sample. The presence of sodium as the predominant exchangeable cation, is increased the swelling several times rather original volume. Hence, Na-MMT used as the major constituent in nonexplosive agents for splitting rock in natural stone quarries. Advantageous properties of montmorillonite made it appropriate for many applications such as use in oil drilling industry as a component of drilling mud, soil additive, component of foundry sand, desiccant to remove moisture from air and gases, catalyst and various medicinal and pharmacological applications. This review article consists the various synthetic methods for preparation of catalysts based on MMT for organic syntheses and assessing their catalytic activities.

Antioxidants are essential and important for plants and animals’ sustenance. They are substances that protect cells from the damage caused by unstable molecules known as free radicals. The sources and origin of antioxidants which include fruits and vegetables, meats, poultry and fish were treated in this study. The types of antioxidants such as ascorbic acid, glutathione, melatonin, tocopherols and tocotrienols were reported. The classification and characteristics of antioxidant; its measurements and level in food and free radicals were also documented. The Chemistry of antioxidants which include chain reactions, molecular structures, food antioxidants and reaction mechanisms, bio-chemical activity and effects of antioxidants were also reviewed. Further, the medicinal applications, pharmacological effects, therapeutic properties and future choice of antioxidants were reported in this review.

Modern research often demands the modular conjugation of molecular systems with functional modules including fluorophores, purification tags, solubility enhancers, isotopic labels, or biologically active ligands, which enable their functional analysis, tracking in complex environments, and aids in several medicinal and pharmaceutical applications. Such molecular systems span several orders of size and complexity and range from small molecules and natural products to polymers, particles, or surfaces in material research and to even whole living organisms in the life sciences. A common way to achieve the functionalization of these systems relies on the incorporation of highly reactive functional groups, which can be easily introduced either by synthetic or biochemical methods. Ideally, these groups are chemically inert to other given functionalities, while still displaying a high level of intrinsic reactivity. Furthermore, these functional groups should be able to form reliably new chemical bonds in high yields as defined for click reactions and with excellent chemoselectivity. Among many reactive functional groups that meet these criteria, azides have certainly been the most popular, as they can be reacted either with alkynes to form triazoles by 1,3dipolar cycloaddition or with P reagents by Staudinger reactions. The development of copper-catalyzed (CuAAC) and strain-promoted azide–alkyne cycloaddition as well as the use of phosphines and phosphites in Staudinger ligations led to numerous labeling and conjugation applications. Azide groups can be introduced easily into small molecules, polymers, and materials by organic synthesis. Along those lines, the high tolerance of azides towards a number of other organic transformations whilst still offering a high reactivity to ensure efficient conversions leads to the ubiquitous application of CuAAC and the commercial availability of many azide-containing functional building blocks. Herein, we introduce a reagent which allows the sequential coupling of two different azido compounds in polar, unpolar, and aqueous solvents by a short reaction sequence. This approach allows the modular coupling of readily available azido-containing functional building blocks by a final metal-free conjugation step. To achieve this formal azide–azide, coupling we wanted to combine the CuAAC with the metal-free Staudinger phosphonite reaction recently advanced in our laboratory. Our proposal led to the design of an alkyne directly attached to borane-protected phosphonite (Scheme 1). The borane protecting group fulfills several purposes, as it ensures that no homo-coupling occurs during

When Staudinger meets Huisgen! A combination of the copper-catalyzed variant of the Huisgen azide–alkyne cycloaddition (CuAAC) and the Staudinger reaction, the two most successful chemoselective reactions for the transformation of azides, leads to a chemical method that allows the sequential coupling of two different azido building blocks in high yields. This modular procedure enables a final metal-free conjugation of functional building blocks to azides. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

La chimie crée son objet. Cette faculté créatrice, semblable à celle de l’art lui-même, la distingue essentiellement des sciences naturelles et historiques. Marcelin Berthelot, La Synthèse chimique, Alcan, Paris, 1887 This famous quote from Marcelin Berthelot (its English translation is “Chemistry creates its object. This creative faculty, similar to that of art itself, distinguishes it essentially from natural and historical sciences.”) exemplifies like no other the ability of the chemist to create new molecules with novel structures and, following therefrom, novel properties. Because of this creative power, chemistry, and in particular synthetic chemistry, has been assigned multiple enabling roles and several of its sister disciplines have grown “chemical” branches such as “chemical physics”.1 Among these disciplines, “chemical biology” is a younger cousin. While the name was coined at least four decades ago,1 the current understanding of the term was shaped only within the last two decades. The field evolved from bioorganic chemistry, biochemistry, cell biology, and pharmacology, but synthetic organic chemists played a leading role in its inauguration. For instance, Stuart L. Schreiber and K. C. Nicolaou served as Editors of the journal Chemistry & Biology, “the first journal dedicated to the expanding intellectual area in which chemical approaches and biological disciplines overlap.” As they stress in their inaugural Editorial in the first issue: “Both of us started professional life as strict organic chemists, with little knowledge of biology and not much expectation that we would ever need to know any.” [2] Since then, the development and application of organic synthesis methodology to achieve a greater understanding of biology at the molecular level has emerged as one major area of research in chemical biology. For instance, labeling of biomolecules has greatly advanced in the last decades, based largely on the development of novel biomacromolecule synthesis and ligation techniques, which are often rooted in classical organic synthesis methods such as the Huisgen 1,3-dipolar cycloaddition and the Staudinger reaction. Among the various applications of organic synthesis methodology in chemical biology research, it is most likely that the use of small-molecule probes as tools for unraveling and manipulating the inner workings of the cell (chemical genetics) today is commonly associated with the term “chemical biology”. While major studies and efforts have been made during the last decades to fill the chemical toolbox required to meet this daunting task and to equip the chemical biologist with the right “tools” in the struggle to decipher the secrets of nature, this endeavor has only just begun. Notably, although large compound libraries are commercially available these days, their structural complexity and diversity remain fairly limited, and in high-content assays, their performance often leaves room for substantial improvement. Higher structural complexity and incorporation of stereogenic centers often positively correlate with bioactivity, thus calling for the synthesis and application of complex compound classes in chemical biology research that expand the currently accessible tool and probe candidates to novel scaffold classes. This demand can only be met by the continuous introduction of novel synthesis methodology and the development of creative solutions to the problem of making increasingly complex compounds available with higher efficiency and practicability in the formats of compound-collection synthesis. Therefore, the synthesis of structurally and stereochemically complex molecular architectures is at the heart of chemical biology research. Chemical biology needs continuous input from organic synthesis, and organic synthesis may find challenging and unprecedented synthesis targets with an immediate application in the problems faced by chemical biologists: chemical biology and organic synthesis are brothers-in-arms! Ideally, to lend the brotherhood strength and to develop it to maximum impact, both chemical and biological expertise should be established under one roof, that is, within a given research group. As ideal as it would be, such an interdisciplinary team is hard to establish. Limitations arise on one hand from the different cultures of the two sciences and the core expertise of the leading scientists, who usually were trained and started their career in either chemistry or biology. On the other hand, establishing and operating a full chemistry and biology infrastructure is very cost-intensive, and funds on the required scale often are simply not available. Hence, only few groups worldwide can fulfill these requirements. Alternatively, collaboration between different research groups is necessary in chemical biology research, and, indeed, many of the best results obtained in this science represent multiteam efforts. If productive collaborations with mutual appreciation of the partners and their scientific contribution can be established, from a scientific point of view, this brotherhood may actually be the better approach to tackle demanding scientific problems. The combined expertise of the partners in chemistry and biology usually will allow deeper insights to be obtained and high-quality research in both sciences to be performed. This brotherhood may prove vital to yet another sector of science in the near future, that is, to drug discovery. Chemical biology is partly rooted in cell biology and pharmacology, and its repertoire of methods extents into small-molecule synthesis, determination of bioactivity, and identification and validation of small molecule cellular targets. If the small molecules employed in chemical biology research have druglike properties, and modulation of the activity of their cellular targets can be tied to a disease-modifying effect, the link to drug discovery is obvious. In fact, fully fledged chemical biology research programs have the potential to simultaneously produce novel insights into fundamental biological mechanisms, deliver new targets, and supply small-molecule modulators of target activity. Therefore, major challenges in drug discovery may inspire chemical biology research and by extension, organic synthesis endeavors. Conversely, the outcomes of a chemical biology investigation may fuel efforts in drug discovery. This alliance may prove instrumental as a key driver for future research in the pharmaceutical industry. Facing major challenges, pharmaceutical companies very recently have increased collaboration with academic institutions far beyond the occasional support of individual smaller projects (see, for example, reference 3). In so doing, the industry may be well advised to listen to its own opinion leaders. In June 2011, Mark Bunnage (Pfizer) wrote: “This change in model reflects the reality that the vast majority of the initial breakthroughs in target biology research occurs in the academic research environment. It is thus considered essential for pharmaceutical companies and their scientists to become better connected with the external research environment and develop a more extended network of partnerships and genuine collaborations with academia. …︁ It is thus essential for medicinal chemists in industry to increase their awareness of chemical biology approaches and build these into their armamentarium to enable drug discovery.” [4]—He is right! A successful and seminal example of such a fruitful collaboration between academia and industry is the Chemical Genomics Centre (CGC) of the Max Planck Society (Max-Planck Gesellschaft, MPG). The CGC was established in 2005 as a joint initiative of the MPG, Merck KGaA, Schering AG, Bayer CropScience AG, and Organon B.V. Research in the CGC is focused on challenging unsolved problems in chemistry and biology of major relevance to drug discovery, such as stabilization of protein–protein interactions by small molecules and the development of allosteric kinase inhibitors. Both the companies and the MPG funded independent research groups that developed the basic science and transferred it to the companies. If appointment of the group leaders to professorships and integration of the developed technologies into the internal project pipelines of the companies are accepted as stringent criteria for measuring success from both the academic and the industrial point of view, then the establishment of the CGC was a major success. Accordingly, after the first funding period of the CGC (2005–2010) the MPG and Merck KGaA, AstraZeneca AB, Boehringer Ingelheim Pharma GmbH & Co. KG, Bayer Pharma AG, and Bayer CropScience AG have established “CGC II”, and the first research group leaders have been appointed very recently. The success of the CGC and related initiatives suggests that it may be more than advisable to those engaged in drug discovery to take the final verses of Schiller’s poem “The Hostage” to heart (translation by Scott Horton):5 He gazed upon them long in amazement, And then spoke: “You have succeeded, You have turned my heart, In truth, fidelity is no idle delusion, So accept me also as your friend, I would be—grant me this request— The third in your band!”

Revolution in organic compound synthesis has been promoted by microwave‐assisted organic syntheses (MAOS) by which small molecules are built up into large polymers in a fraction of time. Ionic liquids (ILs), considered being a relatively recent magical chemical due to their unique properties, have a large variety of applications in all areas of the chemical industries. Nonvolatility and nonflammability are their common characteristics giving them an advantageous edge in various applications. This common advantage, when considered with the possibility of tuning the chemical and physical properties of ILs by changing anion–cation combination, is a great opportunity to obtain task‐specific ILs for a multitude of specific applications. In previous reviews on this subject, the focus of MAOS has been on the process of MAOS reactions rather than the importance given to the related applications. This review focuses on properties of ILs and their use in organic synthesis of heterocyclic compounds under microwave exposure. In this review, a general description of ILs and historical background are given; basic properties of ILs such as solvent properties are discussed; structure of ILs, cation, anion types, and synthesis methods in the related literature and synthesis of different heterocyclic compounds in ILs are briefly summarized.

Organic synthesis has long played a pivotal role in the chemical sciences. It is therefore unsurprising and appropriate that the International Conferences on Organic Synthesis (ICOS) continue to thrive. This series was initiated by IUPAC in 1976 and has since featured biennially as one of the core events of the Union. What is surprising is that 22 years have elapsed since an ICOS event was last hosted by Japan. On that occasion, ICOS-4 was held in 1982 at Shinjuku, Tokyo, and was acclaimed as a great success. The latest event (ICOS-15), in Nagoya, Japan on 1ñ6 August 2004, offered an opportunity to match or surpass the impact of its predecessoróa challenge that was taken up enthusiastically under the leadership of Profs. Minoru Isobe (Nagoya University) and Hisashi Yamamoto (now at the University of Chicago) as Conference co-Chairs. Almost 1000 participants converged on Nagoya from all parts of the world. A noticeably high level of participation by delegates from East Asia in relation to those from North America and Europe attested to the growing capacity of this region to contribute to research at the forefront of this area of the chemical sciences. The scientific program of the Conference embraced all aspects of modern synthetic organic chemistry, inter alia, the invention of selective synthetic methods, asymmetric synthesis, total synthesis of natural products, design and synthesis of artificial agents for pharmaceutical and agricultural uses, and molecular assembly and materials based on molecular function. This topical breadth was also captured in a poster program, which was handsomely supported by no less than 466 displays on every conceivable facet of the subject. Overall, it is evident that organic synthesis has expanded its boundaries increasingly toward biological and material sciences, in response to the new challenges arising from rapid progress in molecular biology and applied physics during recent years. A lecture program comprising 10 plenary and 20 invited presentations, in addition to the Thieme/IUPAC award lecture and two Nagoya medal lectures, contributed to a truly exciting Conference experience, and the 21 speakers who kindly agreed to contribute papers based upon their presentations have made it possible to capture some of the excitement in this issue of Pure and Applied Chemistry. The Nagoya Gold Medallist, J. F. Stoddart, used the occasion to share an absorbing and very personal perspective on molecular assembly and materials, a theme on which M. Fujita also disclosed new insights and developments. The perennial theme of total synthesis of natural products, provided scope for presentation of highly creative accomplishments by S. Ley, J. Cossy, Y. Langlois, R. Pilli, and S. Kozmin on a variety of challenging targets. Such advances in the total synthesis of biologically active natural products having extremely complex structures, often necessitate development of novel synthetic methods, and H. Overkleeft, P. Chiu, V. Nair, T.-P. Loh, S. Martin, T.-Y. Luh, E. Juaristi, and M. Catellani did justice to this theme with presentations on a variety of extremely elegant and sophisticated new developments in methodology, based upon organometallic catalysts and/or reagents. Finally, the broad theme of asymmetric synthesis using organometallic complexes with chiral ligands or chiral organocatalysts was developed in conjunction with combinatorial methodology, which is shown to be highly effective in optimizing catalytic systems. Those who contributed to the topic of asymmetric synthesis are K. Ding, A. Charette, S. H. Kang, A. Berkessel, and K. Maruoka, the recipient of the Nagoya Silver Medal. What is the future of organic synthesis? The invention of unprecedented drugs and materials has enriched and expanded the horizons of the human experience in formerly unimagined ways, and owes much to the ever increasing ingenuity of organic synthesis, and recognition and attainment of new synthetic targets. The impact of organic synthesis on cognate disciplines and on general advancement of science and technology is definitely enormous and will be further strengthened by future challenges and opportunities. Thus, it is hoped that younger generations will be inspired to participate in tapping this rich potential, in the cause of advancing science and contributing to the enrichment of future life. These aspirations may yield incalculable rewards. Such progress will certainly be reflected in the scientific program of the next Conference in the ICOS series, which will take place in Merida, Yucatan, Mexico on 11ñ15 June 2006, under the chairmanship of Dr. Eusebio Juaristi, Instituto Politecnico Nacional, Mexico. Tamejiro Hiyama Conference Editor Department of Material Chemistry Kyoto University, Kyoto, Japan *An issue of reviews and research papers based on lectures presented at the 15th International Conference on Organic Synthesis (ICOS-15), held in Nagoya, Japan, 1-6 August 2004, on the theme of organic synthesis. Other presentations are published in this issue, pp. 1087-1296.