Enantioselective syntheses O 0031Asymmetric Morita-Baylis-Hillman Reaction Catalyzed by Isophoronediamine-Derived Bis(thio)urea Organocatalysts. -Compounds (Ia), (Ic), and (Id) are found to be very active and enantioselective catalysts for the title reaction. Especially the reaction of aldehyde (VII) with cyclohexenone (III) in the presence of catalytic amounts of bis(thiourea) compound (Ic) in combination with the novel base (Ib) affords product (VIII) with high yield and enantioselectivity. -(BERKESSEL*, A.; ROLAND, K.; NEUDOERFL, J. M.; Org. Lett. 8 (2006) 19, 4195-4198; Inst. Org.

Other 6-membered heterocycles R 0670A Family of New 1,2,4-Trioxanes by Photooxygenation of Allylic Alcohols in Sensitizer-Doped Polymers and Secondary Reactions. -The syntheses of several 1,2,4-trioxanes from the reaction of 1,2-hydroperoxy alcohols with aldehydes and ketones, or acetals and orthoesters are reported. The hydroperoxy alcohols are obtained by a recently published Type II photooxygenation (singlet oxygen) using polymeric sensitizer-adsorbed or covalently sensitizer-doped polymeric (macro-or nanosized) containers. The method of trans-peroxyacetalization of acetals for the synthesis of 1,2,4-trioxanes is found to be superior to the direct use of aldehydes. -(BARTOSCHEK, A.; EL-IDREESY, T. T.; GRIESBECK*, A. G.; HOEINCK, L.-O.; LEX, J.; MIARA, C.; NEUDOERFL, J. M.; Synthesis 2005, 14, 2433-2444; Inst.

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Abstract:The cobalt(II) complex of the Halterman porphyrin, 5,10,15,4R,5R,2,3,4,5,6,7,4:5,porphyrinato cobalt(II) [Co(por*)], was synthesized and its structure was identified by X-ray analysis. Up to 80:20 trans:cis diastereomeric ratio and 82% ee were achieved in the cyclopropanation of styrene with ethyl diazoacetate by using this cobalt(II) porphyrin complex as catalyst.

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