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Professor Janine Cossy

Title: The Power of Transition Metals. Construction and Functionalization of Heterocycles

 

Abstract: Heterocycles are present in a great diversity of natural products and/or bioactive compounds. They are also present in ligands, dyes, materials, etc. Due to the importance of heterocycles, it is important to develop efficient and versatile chemoselective methods to access these compounds. In this lecture, different methods will be presented to acess functionalized heterocycles containing oxygen and nitrogen. Depending on the synthetic target to be reached, we will show that transition metals such as gold, iron, cobalt or rhodium are excellent synthetic tools to realize either the functionalization and/or the construction of heterocycles.

Professor Troels Skrydstrup

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Recent Developments in Carbonylation Chemistry

Abstract: Carbonylation reactions represent important chemical transformations for the introduction of oxygen containing functionalities. Transition metal complexes play a key role for promoting  this chemistry. In this talk, I provide a short overview on the use of CO surrogates for performing safe and stoichiometric carbonylation chemistry. Examples are given for the synthesis of pharmaceutically relevant molecules, but also for efficient late-stage introduction of carbon isotopes into bioactive molecules, aiding drug metabolism and pharmacokinetic (DMPK) studies in drug development programs [1–5]. Furthermore, I will elaborate on our initial efforts to exploit this chemistry for the development of a molecular surgery strategy for extruding an embedded carbon atom within the bioactive molecule’s framework, and its replacement with a carbon isotope via a sequence of C–C bond cleaving and bond forming events (Scheme 1) [6].

References:
1. Andersen, T. L.; Frederiksen, M. W.; Domino, K.; Skrydstrup, T. Angew. Chem. Int. Ed. 2016, 55, 10396; 2. Domino, K.; Veryser, C.; Wahlqvist, B. A.; Gaardbo, C.; Neumann, K. T.; Daasbjerg, K.; De Borggraeve, W. M.; Skrydstrup, T. Angew. Chem. Int. Ed. 2018, 57, 6858; 3. Makarov, I. S.; Kuwahara, T.; Jusseau, X.; Ryu, I.; Lindhardt, A. T.; Skrydstrup, T. J. Am. Chem. Soc. 2015, 137, 14043; 4. Ravn, A. K.; Vilstrup, M. B. T.; Noerby, P.; Nielsen, D. U.; Daasbjerg, K.; Skrydstrup, T. J. Am. Chem. Soc. 2019, 141, 11821; 5. Donslund, A. S.; Pedersen, S. S.; Gaardbo, C.; Neumann, K. T.; Kingston, L.; Elmore, C. S.; Daasbjerg, K.; Skrydstrup, T. Angew. Chem. Int. Ed. 2020, 59, 8099; 6. Ton, S. J.; Neumann, K. T.; Noerby, P.; Skrydstrup, T. J. Am. Chem. Soc. 2021, 143, 17816.

 

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Professor Eric Doris

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Title: Some chemistry using nanohybrid catalysts

 

Abstract: Supported metal nanoparticles are attracting increasing interest because they allow for clean, selective and efficient catalytic transformations. In addition, supporting of the metals offers the possibility to recover the active catalyst, allowing it to be reused. Numerous metals, including gold, have been assembled onto solid supports although metallic gold has traditionally been regarded as a poor catalytic species. The catalytic activity of gold is however dramatically enhanced when downsized to nanoscale. This peculiar behavior of nano-gold has recently boosted its use in fine chemical synthesis applied, for example to selective hydrogenations, carbon-carbon bond formation, or oxidations. Various materials can be used as support for nanoparticles including clays, zeolites, polymers, metal oxides, amorphous carbon, etc. Compared to other supports, carbon nanotubes (CNT) provide advantages that include chemical, thermal and mechanical stability, inertness, high specific surface area, and chemically tunable topography. Moreover, CNTs are electronically active and are likely to contribute to the stabilization of the metals. We recently reported carbon nanotube-based hybrid catalysts that were assembled using a layer-by-layer strategy. These nanohybrids, incorporating various metals, and exhibiting specific catalytic properties, were applied to a wide variety of organic transformations. Some chemistry based on CNT-metal hybrids will be presented.

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Professor Karol Grela

Title: Tuning of neutral carbene ligands—the way to control activity, selectivity and stability of ruthenium olefin metathesis catalysts
 

 

Abstract: Ruthenium-catalyzed olefin metathesis reactions represent an attractive and powerful transformation for the formation of new carbon-carbon double bonds [1]. This area is now quite familiar to most chemists as numerous catalysts are available that enable a plethora of olefin metathesis reactions. However, formation of substituted and crowded double bonds, decreasing the amount of metal, using metathesis in medicinal chemistry, etc. still remain a challenge, making industrial applications of this methodology difficult [1]. These limitations can be solved by designing new, more active and stable catalysts. Sometimes even a small alteration of the catalyst's structure can lead to a visible change of its properties. This was the case in the so-called Grubbs’ second generation ruthenium catalysts featuring neutral N-Heterocyclic Carbene (NHC) ligands [2,3]. Such NHC ligands typically contain large N-alkyl or N-aryl groups (sometimes called “wings” or “arms” of the NHC ligand). During the lecture some examples of possible structural modifications of the NHC ligands will be presented, mostly based on adjusting the relative size of these N-groups [3,4] or by limiting their free movement [5]. Such alterations of the aromatic “wings” in the NHC ligand can be used to affect the resulted ruthenium olefin metathesis catalyst’s activity, selectivity and stability.

References
[1] Olefin Metathesis: Theory and Practice, Grela, K. (Ed.), John Wiley & Sons, 2014.
[2] C. Samojłowicz, M. Bieniek, K. Grela, Chem. Rev. 109. (2009) 3708.
[3] L. Monsigny, A. Kajetanowicz, K. Grela, Chem. Rec. 21. (2021) 3648.
[4] S. Planer, P. Małecki, B. Trzaskowski, A. Kajetanowicz, K. Grela, ACS Catal. 10. (2020), 11394.
[5] W. Kośnik, D. Lichosyt, M. Śnieżek, A. Janaszkiewicz, K. Woźniak, M. Malińska, B. Trzaskowski,
A. Kajetanowicz, K. Grela, Angew. Chem. Int. Ed. (2022), e202201472.

Professor Tomislav Rovis

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Title: Controlling Catalysis with Visible Light

Abstract: Visible light is an abundant energy source that can also be delivered on demand. Harnessing the energy in visible light has recently been accomplished through the use of photoredox catalysis, which can generate radical intermediates by an oxidation or reduction step to initiate a bond formation followed by a return of the electron or hole to close the catalytic cycle. We have been engaged in expanding the versatility of visible light photoredox catalysis and have uncovered strategies to effect C-H activation in unactivated positions of alkanes as well as controlling catalysis spatially and temporally. Reaction development, mechanistic investigations and synthetic applications will be the subject of this lecture.
 

Professor John Bower

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Title: Catalytic Chirality Generation: New Strategies for Organic Synthesis

Abstract: Our group develops new catalysis platforms that enable the efficient generation of chiral building blocks and heterocyclic scaffolds. Current priority areas include: (i) the development of catalytic C-C bond activation processes and associated cycloadditions [1], (ii) the development of aza-Heck reactions [2], and (iii) the development of enantioselective alkene hydroarylation reactions [3]. Selected recent highlights will be presented. 

 

Representative publications:

[1] Wang, G.-W.; Bower, J. F. J. Am. Chem. Soc. 2018, 140, 2743.

[2] Ma, X.; Hazelden, I. R.; Langer, T.; Munday, R. H.; Bower, J. F. J. Am. Chem. Soc. 2019, 141, 3356.

[3] Grélaud, S.; Cooper, P.; Feron, L. J.; Bower, J. F. J. Am. Chem. Soc. 2018, 140, 9351.

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Professor Debabrata Maiti

Title: Designing of templates to reach the distal C–H bond
 

Abstract: Mimicking the nature has always been a coveted target for scientific communinities. A precise understanding has emerged as to how enzymes accomplish the chemical transformations. Enzymes catalyze inert C-H bond functionalization in a regio- and stereoselective manner using metal-active site. Inspired by the nature, we have developed catalytic methods to functionalize carbon–hydrogen (C–H) bonds which provides significant economic and environmental benefits over traditional synthetic methods. Applicability of our strategies towards synthesis of various complex molecules will be discussed.
 

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Professor Jared T. Shaw

Title: Enantioselective C–H Insertion Reactions of Donor/Donor Carbenes for the Synthesis of Complex Natural Products

Abstract: Rhodium carbenes lacking electron withdrawing groups, or “donor/donor” carbenes, participate in a wide variety of selective reactions. Due to the reduced electrophilicity, these reactive intermediates exhibit remarkable functional group tolerance, enabling access to uniquely complex organic molecules. The development of new methods and their application to the synthesis of a series of complex heterocycles, including several natural products, will be described.

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Professor Pierre Mothé Esteves

Title: Carbon: The Perfect Strange
 

Abstract: “Can you remember, remember my name, As I flow through your life”… This verse of the Deep Purple classic song Perfect Strangers can be applied to our core element in organic chemistry: the carbon atom. Although we may think that we know everything about its structure and pure forms, this element still brings us surprises in the XXI century. We will see that the prediction and synthesis of new carbon allotropes is possible and may represent an inspiring synthetic challenge. We show how new allotropes of carbon, containing atoms with different hybridizations and proportions, can be conceived and synthesized.

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Professor Diego Alves

Title: Synthesis of highly functionalized 1,2,3-triazoles systems through copper- or organocatalysis protocols

Abstract: This presentation will provide a comprehensive overview of reported methods particularly copper- and organocatalyzed reactions - for the regioselective syntheses of high functionalized 1,2,3-triazoles systems. These chemical entities are prevalent cores in biologically active compounds and functional materials. In view of their unique properties, substantial efforts have been paid for the design and development of practical approaches for the synthesis of these scaffolds.

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Professor Annaliese Franz

Title: Organosilicon Chemistry for Enantioselective Synthesis, Catalyst Design and Medicinal Chemistry

Abstract: The successful development of new synthetic methods and catalysts is important for the discovery and production of chiral organic molecules and materials. This talk will highlight several examples of organosilicon chemistry that provide rich opportunities and applications for methodology, mechanism and novel synthetic targets. First, the development of enantioselective synthesis and molecular recognition components involved to access chiral-at-silicon molecules will be presented with applications for the design of new catalyst systems based on siloxy compounds.  Second, the unique reactivity of allylsilane and allenylsilane nucleophiles will be featured to demonstrate opportunities to develop efficient methods for the enantioselective synthesis of complex molecules such as spirooxindoles, as well as interesting opportunities to explore mechanistic features of annulation reactions and Lewis acid-catalyzed reactions. Finally, examples for the synthesis of novel organosilicon targets with medicinal applications will be presented. For all studies, results of structural, mechanistic, kinetics and molecular binding studies will be included to provide insight for catalyst activity, design and synthetic applications.

Professor Elisa S. Orth

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Title: Nucleophilic neutralization of organophoshates: correlating promiscuity (or versatility?) with structure-reactivity-mechanistic trends

 

Abstract: Is the broad mechanistic versatility of nucleophiles towards organophosphate neutralization, that has inspired many catalysts, beneficial or a threateningly promiscuity? We have been working on unravelling this puzzle and show how varying the nature of the organophosphate can lead to N-phosphorylation or unusual N-alkylation. Also, the structure of the neutralizing nucleophile also shows an interesting trend. Should this add to their known versatility or can it be considered an unsought promiscuity? A concise understanding of the mechanism underlying organophosphates will be presented with agrochemicals and chemical warfare simulants, which isimperative for effectively applying in real destruction or monitoring systems. Several pesticides and a Tabun simulant have been efficiently neutralized with a myriad of nucleophilic neutralizing agents. Preferably, one seeks less toxic products and no side reactions. In that sense, we evidence how mechanistic studies and structure-reactivity relationships are valuable tools for modulating towards less toxic products. Moreover, we show that one monitoring system may not apply to various toxic agrochemicals, since their structure can shift the mechanism, hence lead to different products and suppress important signals or give false positives.

Professor Daniel Werz

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Title: Carbopalladation Cascades – Not only syn, but also anti


Abstract: A characteristic feature of carbopalladation reactions is the syn-attack of the organopalladium species LnX[Pd]-R on the reacting π-system [1]. Such a step results in compounds bearing Pd and R on the same side of the originating alkene moiety. Embedded into longer domino sequences complex structures are efficiently obtained by a repetition of this syn-carbopalladation step. In this way, linear oligoynes were cyclized in a dumbbell-mode and led to benzene-type structures or higher oligoenes [1]. We exploited this chemistry to synthesize not only chromans, isochromans [2] and dibenzopentafulvalenes [3], but also to access the most truncated π-helicenes which only consist of a Z,Z,Z,..-oligoene chain that is fixed in an all s-cis arrangement [4]. All these domino processes are based on a syn-carbopalladation cascade. However, a carbopalladation cascade involving formal anti-carbopalladation steps opens new avenues to create compounds with tetrasubstituted double bonds. Such a process was realized, and mechanistically and computationally investigated. The synthetic potential was demonstrated for the preparation of various oligocyclic frameworks (including natural products) by making use of a variety of different terminating processes [5].

 

[1] E. Negishi, G. Wang, G. Zhu, Top. Organomet. Chem. 2006, 19, 1-48; [2] M. Leibeling, D. C. Koester, M. Pawliczek, S. C. Schild, D. B. Werz, Nat. Chem. Biol. 2010, 6, 199; [3] J. Wallbaum, R. Neufeld, D. Stalke, D. B. Werz, Angew. Chem. Int. Ed. 2013, 52, 13243; [4]  B. Milde, M. Leibeling, M. Pawliczek, J. Grunenberg, P. G. Jones, D. B. Werz, Angew. Chem. Int. Ed. 2015, 54, 1331; [5] a) M. Pawliczek, T. F. Schneider, C. Maaß, D. Stalke, D. B. Werz, Angew. Chem. Int. Ed. 2015, 54, 4119. b) M. Pawliczek, B. Milde, P. G. Jones, D. B. Werz, Chem. Eur. J. 2015, 21, 12303; c) A. Düfert, D. B. Werz, Chem. Eur. J. 2016, 22, 16718; d) B. Milde, M. Pawliczek, P. G. Jones, D. B. Werz, Org. Lett. 2017, 19, 1914.

Professor Cristiano Raminelli

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Title: Benzyne Chemistry: Synthetic Methods and Total Syntheses


Abstract: The benzyne chemistry has found applications in organic chemistry, including total syntheses of natural products and preparations of functional materials. In this context, 2-(trimethylsilyl)aryl trifluoromethanesulfonates can be considered an important alternative for the generation of benzyne and derivatives, enlarging the scope of benzyne chemistry applications in preparative organic chemistry. Accordingly, in our lecture we intend to present useful synthetic methods for the preparation of heterocyclic compounds and concise approaches to the total syntheses of natural products and bioactive compounds, involving the generation of benzyne and derivatives via fluoride-induced reactions under mild conditions.

Professor María Laura Uhrig

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Title: From thiosugars and thiodisaccharides to supramolecular multivalent ligands


Abstract: Thioglycosides and thiodisaccharides represent a synthetic challenge for carbohydrate chemists due to their increasing importance in the Glycobiology field. In these compounds, the anomeric oxygen has been replaced by a sulfur atom, and so, they are considered carbohydrate mimetics with great potential as enzyme inhibitors or new ligands for lectins, given that this replacement does not interfere with recognition events. Moreover, this structural feature makes them more resistant towards enzymatic and acidic hydrolysis. Therefore, the development of new synthetic methods to obtain thiosugars and their use as building blocks for the synthesis of new carbohydrate-derived compounds have been an active research field over the years. In our laboratory, we are interested in developing multivalent systems with high affinity for lectins, constructed from glycomimetics such as thiosugars and thiodisaccharides. Thus, after exploring a range of covalently-constructed multivalent structures, we undertook the study of self-assembled multivalent systems produced from amphiphilic compounds. In all cases, we have incorporated thiosugars such as 1-thiolactose, β-S-N-acetylglucosamine and even thiodisaccharides as recognition elements, which were, at the same time, the polar moiety of the amphihile. Pyrene and resorcinarene systems, as well as long chain diacyl-derived tartaric residues, have been used as hydrophobic residues. Thus, in this presentation I will refer to our latest results on the synthesis and characterization of supramolecular multivalent ligands for lectins. It will include the synthetic results regarding the construction of GlcNAc-thiodisaccharides, and also our experience on a variety of self-assembled and micellar systems, including gels, which have shown high affinity for model lectins.

Professor Andy McNally

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Title: Selective Functionalization of Pyridines, Diazines and Pharmaceuticals via Unconventional Intermediates 


Abstract: Pyridines and diazines are ubiquitous in pharmaceuticals and agrochemicals, yet there are limits in synthetic methods that can directly functionalize the C–H bonds in these structures. We will show two distinct approaches, using phosphorus and ring-opened intermediates, that enable selective functionalization of these heterocycles into a range of valuable derivatives. A range of C–C and C–Heteroatom bond formations are viable, and the chemistry functions on structures typically encountered in drug discovery programs. Our lab has also performed mechanistic and computational studies of the regioselectivity of these reactions and the phosphorus ligand-coupling processes involved.

References: 1.   X. Zhang*, K. G. Nottingham*, C. Patel, J. V. Alegre-Requena, J. N. Levy, R. S. Paton, A. McNally, Nature, 2021, 594, 217; 2. B. T. Boyle*, J. N. Levy*, L. D. Lescure, R. S. Paton, A. McNally. ChemRxiv., 2022. https://doi.org/10.26434/chemrxiv-2022-88802-v3

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Professor Ross Denton

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Title: Organocatalytic Alcohol Activation


Abstract: Nucleophilic substitution reactions are fundamental transformations in organic synthesis because they allow readily available alcohols to be converted into a wide variety of functional groups with predictable inversion of stereochemistry. However, they are inherently wasteful since alcohol activation is necessary and takes place at the expense of a stoichiometric reagent. The lecture will describe the design and development of organocatalytic platforms for catalytic nucleophilic substitution reactions of alcohols and epoxides as well as applications in natural product and active pharmaceutical ingredient synthesis.

Gabriel Kaetan Baio Ferreira, Ph.D.

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Title: Exploring the new retrosynthesis tool from CAS SciFinder-n

 

Customer Success Specialist, CAS

 

Gabriel has a Bachelor, a M.Sc., and a Ph.D. degree in Chemistry from Universidade Federal do Parana (Curitiba, Brazil). Has six years of experience in chemical research with emphasis on Inorganic and Bioinorganic Chemistry, Materials Science, Catalysis and Chemical Synthesis, working in research labs in Brazil and Spain. In academic area, has experience as a professor of Inorganic Chemistry at high school, undergraduate and graduate level. Currently works as a Customer Success Specialist at CAS, a division of the American Chemical Society, supporting new sales, renewals, ensuring a great user experience on platforms that provide scientific and technological information to support researchers and innovators on their newest discoveries and developments.

Valtair Severino dos Santos Junior, M.Sc.

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Title: How can ACS help promote lab safety culture in the universities

 

Customer Success Specialist, ACS Publications

BSc in Technological Chemistry from Universidade Federal de Minas Gerais (2019), and BEd in Chemistry from Universidade de Franca (2021). Currently, He is pursuing an MSc degree in Pharmaceutical Sciences at Universidade Federal de Minas Gerais (2020-now). His research interests focuses on about organic chemistry, natural products, medicinal chemistry, and chemoinformatics. Also he's enrolled as a Customer Success Specialist at ACS Publications, a division of the American Chemical Society (ACS) in Brazil, promoting scientific information assessment and helping Brazilian users to access scientific contents to support their R&D activities.

Professor László Kürti

Title: Advances in the Synthesis and Application of Strained-Ring Compounds: Catalytic & Stoichiometric Approaches

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