The halogen atom transfer radical cyclization (HATRC) has been evaluated on N-(indolylmethyl)trichloroacetamides under Cu(I)Cl catalysis using nitrogen containing ligands. The ring closure leads to the formation of 3,3-spiro-3H-indoles in moderate to good yields by a 5-exo-mechanism. Derivatives with an N-electron withdrawing substituent also lead to a 5-exo-trig and not to a 6-endo-trig cyclization.
A key intermediate for the synthesis of Tyromycin A, a C-20 tetrachlorodicarboxylic acid, was produced in six steps starting with the dimerization of methyl 10-undecenoate which was obtained from a renewable resource, e.g. castor oil. The acyloin condensation product was then oxidized, transformed to the diene, followed by ozonization, chlorination and finally oxidation to the corresponding tetrachlorodicarboxylic acid.
An industrial project is developed to optimize the chemically catalysed biodiesel production from crude palm oil. This process is intended to be applied on a one ton scale and to be used on the palm oil production facility in equatorial Africa (Ivory Coast and later Cameroon). The produced biodiesel is consumed for the fleet of the company. Because of the specific conditions (unrefined oil with possibly high acidity as starting material, application on the field in technologically difficult conditions), it was essential for the developed proc edure to be robust and simple, and to use the minimal amounts of chemicals. The process was optimised on lab-scale, up-scaled in the following year, and is since then successfully applied as intended, on t he palm oil plantation. The produced biodiesel is used in pure form, without mixing with petroleum fuel and without additives. Even after several years of continuous use, no negative effects were noticed on the engines. The process efficiency and durability are ultimately confirmed and described.
Synthesis of Highly Functionalized Spiro-Indoles by a Halogen Atom Transfer Radical Cyclization. -The title reaction is evaluated on indole derivatives (III) and (V) under Cu(I)Cl catalysis using nitrogen-containing ligands. The ring closure leads to formation of 3,3-spiro-indoles (IV) and (VI), resp., by a 5-exo-cyclization mechanism. -(STEVENS*, C. V.; VAN MEENEN, E.; EECKHOUT, Y.; VANDERHOYDONCK, B.; HOOGHE, W.; Chem. Commun. (Cambridge) 2005, 38, 4827-4829; Dep. Org. Chem., Fac. Biosci. Eng., Univ. Gent, B-9000 Gent, Belg.; Eng.) -M. Paetzel 07-124
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