Iridium-Catalyzed Asymmetric Intramolecular Allylic Amidation:Enantioselective Synthesis of Chiral Tetrahydroisoquinolines and Saturated Nitrogen Heterocycles

For the first time iridium catalysis has been used for the synthesis of chiral tetrahydroisoquinolines with excellent yields and high enantioselectivities (see scheme; cod=1,5-cyclooctadiene, DBU=1,8-diazabicyclo[5.4.0]undec-7-ene). These products are important chiral building blocks for the synthesis of biologically active compounds, in particular alkaloids

Taste processing in Drosophila larvae.

The sense of taste allows animals to detect chemical substances in their environment to initiate appropriate behaviors: to find food or a mate, to avoid hostile environments and predators. Drosophila larvae are a promising model organism to study gustation. Their simple nervous system triggers stereotypic behavioral responses, and the coding of taste can be studied by genetic tools at the single cell level. This review briefly summarizes recent progress on how taste information is sensed and processed by larval cephalic and pharyngeal sense organs. The focus lies on several studies, which revealed cellular and molecular mechanisms required to process sugar, salt, and bitter substances

The Ol1mpiad: concordance of behavioural faculties of stage 1 and stage 3 Drosophila larvae

This publication hasn't any creative commons license associated. This article has a Company of Biologists User Licence 1.1. The deposited article version contains attached the supplementary materials within the pdf.Mapping brain function to brain structure is a fundamental task for neuroscience. For such an endeavour, the Drosophila larva is simple enough to be tractable, yet complex enough to be interesting. It features about 10,000 neurons and is capable of various taxes, kineses and Pavlovian conditioning. All its neurons are currently being mapped into a light-microscopical atlas, and Gal4 strains are being generated to experimentally access neurons one at a time. In addition, an electron microscopic reconstruction of its nervous system seems within reach. Notably, this electron microscope-based connectome is being drafted for a stage 1 larva - because stage 1 larvae are much smaller than stage 3 larvae. However, most behaviour analyses have been performed for stage 3 larvae because their larger size makes them easier to handle and observe. It is therefore warranted to either redo the electron microscopic reconstruction for a stage 3 larva or to survey the behavioural faculties of stage 1 larvae. We provide the latter. In a community-based approach we called the Ol1mpiad, we probed stage 1 Drosophila larvae for free locomotion, feeding, responsiveness to substrate vibration, gentle and nociceptive touch, burrowing, olfactory preference and thermotaxis, light avoidance, gustatory choice of various tastants plus odour-taste associative learning, as well as light/dark-electric shock associative learning. Quantitatively, stage 1 larvae show lower scores in most tasks, arguably because of their smaller size and lower speed. Qualitatively, however, stage 1 larvae perform strikingly similar to stage 3 larvae in almost all cases. These results bolster confidence in mapping brain structure and behaviour across developmental stages.Fundação para a Ciência e a Tecnologia grants: (SFRH/BPD/75993/2011EXPL/BEX-BID/0497/2013); Cluster of Excellence Cells in Motion; CiM International Max Planck research school; Spanish Ministry of Economy and Competitiveness; ‘Centro de Excelencia Severo Ochoa 2013-2017’ grant: (SEV-2012-0208); CERCA Programme/Generalitat de Catalunya; the ‘la Caixa’ International PhD Programme; Spanish Ministry of Science and Innovation grant: (BFU2011-26208); Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz; State of Sachsen-Anhalt; Center for Behavioral Brain Sciences Magdeburg; Otto von Guericke Universität Magdeburg; Deutsche Forschungsgemeinschaft grants: (CRC 779 Motivated behaviour: B11; GE1091/4-1, SPP 1926, Next generation optogenetics, SO1337/2-1, CRC 779 Motivated behaviour: B15; YA272/2-1, PA 787/7-1, (TH1584/1-1, TH1584/3-1); European Commission grant: (FP7-ICT project Miniature Insect Model for Active Learning MINIMAL); Howard Hughes Medical Institute; European Research Council grant: (ERC-2012-StG 309832-PhotoNaviNet); Swiss National Science Foundation grant: (31003A_169993); Landesforschungsförderung Hamburg grant: (LFF-FV27); Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz; State of Sachsen-Anhalt; Center for Behavioral Brain Sciences Magdeburg; Cluster of Excellence ImmunoSensation; Baden-Württemberg Stiftung; Zukunftskolleg of the University of Konstanz.info:eu-repo/semantics/publishedVersio

Copper catalyzed enantioselective allylic substitution by MeMgX

Methyl Grignard undergoes highly regio (>90/10) and enantioselective (ee 91–96%) copper catalyzed allylic substitution on cinnamyl-type chlorides. CuBr (3%) and 3.3% of a chiral phosphoramidite ligand are sufficient for a complete reaction. The synthesis of a precursor of (+)-Naproxen is described. The reaction can be extended to alkyl substituted allylic chlorides (ee 72%)

Tandem Copper-catalyzed enantioselective allylation-metathesis

Grignard reagents undergo enantioselective (up to 86% ee) copper-catalyzed S(N)2' substitution on achiral allylic chlorides. The reaction is wide in scope for both the Grignard reagent and the allylic substrate. The resulting terminal alkene could be submitted to intra- or intermolecular metathesis to afford new chiral synthons. The experimental conditions are compatible with a one-pot overall substitution-metathesis procedure without loss of enantioselectivity