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Monheim, Germany

Bayer AG is a German chemical and pharmaceutical company founded in Barmen , Germany in 1863. It is headquartered in Leverkusen, North Rhine-Westphalia, Germany and well known for its original brand of aspirin. Bayer's primary areas of business include human and veterinary pharmaceuticals; consumer healthcare products; agricultural chemicals and biotechnology products; and high value polymers. The company turned 150 years old on 1 August 2013. Wikipedia.

Due to their strong antiproliferative activity and their unprecedented structural complexity within the class of indole alkaloids, avrainvillamide and stephacidin B have recently attracted considerable interest from the synthetic community. To date, three distinct approaches towards these molecules have been disclosed and the present tutorial review aims at comparing all three syntheses with a focus on the various strategies and methods employed. Besides, recent progress towards the synthesis of structural analogs and the identification of the biological target of avrainvillamide will be presented. © 2010 The Royal Society of Chemistry.

Lummen P.,Bayer CropScience
Advances in Insect Physiology | Year: 2013

As a key intracellular messenger, calcium is involved in the regulation of diverse cellular processes in vertebrate and invertebrates. In excitable cells, voltage-gated calcium channels transform electrical signals into intracellular calcium transients which trigger physiological processes such as muscle contraction or neurotransmitter release. ATP-driven pumps and ion transporters terminate calcium signals by reducing the intracellular concentrations to resting levels. It is, therefore, conceivable that calcium homeostasis and signaling are attractive targets for future insecticide discovery. The first examples proving the validity of this concept are specific peptide toxins blocking insect voltage-gated calcium channels and the new diamide insecticides targeting ryanodine-sensitive release channels. © 2013 Elsevier Ltd.

Jeschke P.,Bayer CropScience
Pest Management Science | Year: 2010

The past 30 years have witnessed a period of significant expansion in the use of halogenated compounds in the field of agrochemical research and development. The introduction of halogens into active ingredients has become an important concept in the quest for a modern agrochemical with optimal efficacy, environmental safety, user friendliness and economic viability. Outstanding progress has been made, especially in synthetic methods for particular halogen-substituted key intermediates that were previously prohibitively expensive. Interestingly, there has been a rise in the number of commercial products containing 'mixed' halogens, e.g. one or more fluorine, chlorine, bromine or iodine atoms in addition to one or more further halogen atoms. Extrapolation of the current trend indicates that a definite growth is to be expected in fluorine-substituted agrochemicals throughout thetwenty-first century. A number of these recently developed agrochemical candidates containing halogen substituents represent novel classes of chemical compounds with new modes of action. However, the complex structure-activity relationships associated with biologically active molecules mean that the introduction of halogens can lead to either an increase or a decrease in the efficacy of a compound, depending on its changed mode of action, physicochemical properties, target interaction or metabolic susceptibility and transformation. In spite of modern design concepts, it is still difficult to predict the sites in a molecule at which halogen substitution will result in optimal desired effects. This review describes comprehensively the successful utilisation of halogens and their unique role in the design of modern agrochemicals, exemplified by various commercial products from Bayer CropScience coming from different agrochemical areas. © 2009 Society of Chemical Industry.

Grondal C.,Bayer CropScience | Jeanty M.,RWTH Aachen | Enders D.,RWTH Aachen
Nature Chemistry | Year: 2010

The total synthesis of natural products and biologically active compounds, such as pharmaceuticals and agrochemicals, has reached an extraordinary level of sophistication. We are, however, still far away from the 'ideal synthesis' and the state of the art is still frequently hampered by lengthy protecting-group strategies and costly purification procedures derived from the step-by-step protocols. In recent years several new criteria have been brought forward to solve these problems and to improve total synthesis: atom, step and redox economy or protecting-group-free synthesis. Over the past decade the research area of organocatalysis has rapidly grown to become a third pillar of asymmetric catalysis standing next to metal and biocatalysis, thus paving the way for a new and powerful strategy that can help to address these issues g- organocatalytic cascade reactions. In this Review we present the first applications of such asymmetric organocascade reactions to the total synthesis of natural products. © 2010 Macmillan Publishers Limited.

Bayer CropScience | Date: 2015-10-30

The novel active compound combinations comprising compounds of the formulae (I) and (II) have very good insecticidal and acaricidal properties.

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