4.2.8. Reductive Coupling 3109 5. Reaction of Aromatic Compounds 3110 5.1. Electrophilic Substitutions 3110 5.2. Radical Substitution 3111 5.3. Oxidative Coupling 3111 5.4. Photochemical Reactions 3111 6. Reaction of Carbonyl Compounds 3111 6.1. Nucleophilic Additions 3111 6.1.1. Allylation 3111 6.1.2. Propargylation 3120 6.1.3. Benzylation 3121 6.1.4. Arylation/Vinylation 3121 6.1.5. Alkynylat...

This paper describes the substrate specificity, synthetic scope, and efficiency of aldolase catalytic antibodies 38C2 and 33F12. These antibodies use the enamine mechanism common to the natural Class I aldolase enzymes. Substrates for these catalysts, 23 donors and 16 acceptors, have been identified. The aldol acceptor specificity is expected to be much broader than that defined here since all ...

Ieodomycin B, which shows in vitro antimicrobial activity, was isolated from a marine Bacillus species. A novel asymmetric total synthetic approach to ieodomycin B using commercially available geraniol was achieved. The approach involves the generation of 1,3-trans-dihydroxyl at C-3 and C-5 positions via a Crimmins-modified Evans aldol reaction and a chelation-controlled Mukaiyama aldol reactio...

Cyanosilylation, aldol coupling and asymmetric Henry reactions were carried out with L- D-valmet ligands in different configurations: i) coordinated to sodium ions, as organocatalysts, week base properties, ii) complexes copper(II), homogeneous catalysts, iii) immobilized copper(II) onto graphene oxide (GO) heterogeneous catalysts. For the reaction of benzaldehyde nitromethane water these affor...

Two convenient methodologies have beendescribed for the enantiospecific synthesis of (–)-valeranone 1. The hydrindanone 12, obtained from the readily andabundantly available monoterpene (R)-carvone,has been converted into the ketoaldehyde 16via the alkene 15b. In anotherdirection the lactone 18, obtainedfrom the hydrindanone 12, has beenelaborated into the ketoaldehyde 16employing two methodolo...

An organocatalytic quadruple cascade initiated by a Friedel-Crafts-type reaction is described. The (S)-diphenylprolinol trimethylsilyl ether catalyzed reaction yields highly functionalized cyclohexenecarbaldehydes bearing a 1,1-bis[4-(dialkylamino)phenyl]ethene moiety and three contiguous stereogenic centers. The reaction tolerates various functional groups and all products are obtained with ve...

The title compound, C(17)H(15)ClO, was prepared from 3,4-dimethyl-benzaldehyde and 4-chloro-hypnone by Aldol condensation. The dihedral angle formed by the two benzene rings is 48.91 (8)°. Only van der Waals forces affect the packing.

[formula: see text] A novel pentacyclic polyhydroxylated sterol, xestobergsterol A (1a), has been synthesized in 24 steps and in good overall yield from stigmasterol 17. The key steps of the synthesis are the Breslow remote functionalization of the polyoxygenated steroid derived from 25 and the base-catalyzed epimerization-aldol condensation of the dione derived from 27.

Tetrahydroxanthenones, which can be easily prepared by a domino oxa-Michael aldol condensation, offer various possibilities for diastereoselective functionalization, giving access to the stereocontrolled synthesis of stereochemical triades or tetrades, which represent privileged structural motifs. In most cases, the relative stereochemistry was unequivocally established by crystal structure ana...

The title compound, C(15)H(17)FO, was prepared directly from the aldol condensation of cyclo-octa-none with 4-fluoro-benz-aldehyde, catalysed by Pd(Ni,Ce) in the presence of trimethyl-silyl chloride. The eight-membered ring adopts a boat-chair conformation.