Rakennuspalikoita luonnosta ihmisen hyvinvointiin ja terveyteen vihreän kemian keinoin

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1 Rakennuspalikoita luonnosta ihmisen hyvinvointiin ja terveyteen vihreän kemian keinoin Kristiina Wähälä Kestävä kemia mahdollisuuksia vihreään kasvuun Helsinki, Finland Matemaattis-luonnontieteellinen tiedekunta

2 Rakennuspalikoita luonnosta ihmisen hyvinvointiin ja terveyteen vihreän kemian keinoin Kristiina Wähälä Kemian laitos Helsingin yliopisto Matemaattis-luonnontieteellinen tiedekunta / Henkilön nimi / Esityksen nimi

3 Green Chemistry is the use of chemistry for pollution prevention. More specifically, Green Chemistry is the design of chemical products and processes that are more environmentally benign. Green Chemistry is a philosophy that seeks to reduce the environmental impact of chemical processes and products. It can be considered as chemists aspiring to the principles of Sustainable Development people, planet, profit.

4 12 Principles of Green Chemistry 1. Prevention of waste 2. Atom economy 3. Less Hazardous Chemical Syntheses 4. Designing Safer Chemicals 5. Safer Solvents and auxiliaries 6. Energy Efficiency 7. Renewable Feedstocks 8. Reduce Derivatisation 9. Catalysis 10. Design for Degradation 11. Real-time analysis for Pollution Prevention 12. Inherently Safer Chemistry for Accident Prevention

5 One step Safe No wasted reagents Atom economy THE IDEAL SYNTHESIS Environmentally acceptable Available materials Simple 100 % yield Matemaattis-luonnontieteellinen tiedekunta / Henkilön nimi / Esityksen nimi

6 Solvent The compound present in greatest quantity is the solvent Liquid at room temperature Choosing solvent The effect that the solvent has on the chemical reaction s products, mechanism, rate of equilibrium Stability of substrates, products and catalysts, transition states, intermediates, in the solvent Suitable liquid temperature range for useful reaction rates Sufficient solvent volatility for removal from the product by evaporation or distillation Cost, which is a particularly important consideration when scaling up for industrial applications

7 Reactions in water Excellent solvent dissolving ionic compounds Ability to form H-bonds High boiling point, melting point, critical temperature 374 C (CO C) Polar and therefore easy to separate from apolar solvents Nonflammable and incombustible Cheap and widely available Odourless and colourless Density is sufficiently different from most organic substances to allow convenient separation

8 Multiphasic Solvent Systems The poor solubility of organic compounds in water 1. Addition of co-solvent 2. Rapid stirring, ultrasound, mw, heating 3. Use of detergents and surfactants 4. Phase Transfer Catalysts Aqueous-organic biphasic catalysis is the most extensively studied biphasic method: hydrogenations, hydroformylations, oxidations, C-C coupling, olefin metathesis and polymerizations Although out of fashion for many years, stoichiometric organic reactions are also becoming increasingly common in water

9 Supercritical fluids Carbon dioxide Chemically inert, nonflammable, nonprotic, inert to radical and oxidizing conditions, non toxic, although greenhouse gas, can be obtained in large quantities as a by-product of fermentation and is easily exacted from the atmosphere Facile separation of products Pharmaceutical industry, cosmetics, food and electronics Steel reactors

10 Key Features of Ionic Liquids Liquid range of 300 C ( C) Excellent solvents for organic, inorganic and polymeric materials Catalysts as well as solvents Highly solvating - low volumes used No measurable vapour pressure Non-flammable Thermally stable under conditions up to 200 C Display Brønsted, Lewis and super acidity Electric conductivity Biphasic systems possible Liquid crystalline structures Ionic Liquids: Designer Solvents for Green Synthesis by Kenneth R. Seddon, ChemFiles, Enabling Technologies, Ionic Liquids, Vol. 5, 2005

11 C-H CATLAB Ansa-aminoboranes K. Chernichenko, Timo Repo, et al. JACS, 2016,

12 Organic chemistry synthesis Friedel-Crafts alkylation and acylation Heck ja Suzuki coupling Oxidation and reduction reactions Asymmetric hydrogenation Oligomerization and polymerization Cracking Arom. sulfonation, nitration, halogenation Diazonisation Diels-Alder-reactions N-ja O-alkylations Aldol- condensation 12

13 Lignin valorization Enzymes chemical catalysis Jussi Sipilä, Annele Hatakka, Kristiina Hilden, Ronald de Vries, Paula Nousiainen University of Helsinki

14 Wood harvesting waste LuKe Stilbenes and lignans from roots of Norway spruce Latva-Mäenpää H., Laakso T., Sarjala T., Wähälä K. & Saranpää P. Trees 2013; Holzforschung 2013

15 LuKe Latva-Mäenpää H., Laakso T., Sarjala T., Wähälä K. & Saranpää P. Trees 2013; Holzforschung 2013 Matemaattis-luonnontieteellinen tiedekunta / Henkilön nimi / Esityksen nimi

16 Cancer drugs Semisynthetic derivatives

17 Betulin from the white outer bark of birch (up to 30% of dry weight) Green Chem., 2016, 18, Matemaattis-luonnontieteellinen tiedekunta / Henkilön nimi / Esityksen nimi

18 Synthetic drugs versus natural product In the laboratory or large scale synthesis of complex natural products, there are two major hurdles: 1) first, the large number of reaction steps often needed, and 2) the need for efficient stereocontrol in those steps. Consider a 20-step synthetic sequence, each proceeding in 50% yield. The overall yield is then = 0,00009 %. For example then, 1000 moles of the starting material would give 0,09 moles of the product. Another problem is the stereochemistry consideration. Very often, laboratory reactions giving good enantiomeric purity are 1) expensive and 2) wasteful, whereas the compounds isolated from Nature are quite often the pure enantiomers. Matemaattis-luonnontieteellinen tiedekunta / Henkilön nimi / Esityksen nimi