Abstract In this paper, the synthesis of carbon skeleton cotylenin A aglycone is described. The key reactions, including an intramolecular aldol reaction, coupling and a ring-closing meta­thesis, allow for effective stereoselective access to aglycone. stereochemistry was confirmed by single-crystal X-ray crystallographic analyses related compounds.

Asymmetric catalysis of the Mukaiyama aldol reaction has been reported with complexes derived from Al, B, Sn(II), and Ti(IV).l The levels of asymmetric induction for the addition of propionate-, isobutyrate-, and acetate-derived silyl thioketene acetals to aldehydes parallel those obtained with chiral-auxiliarybased methodologies.2 However, silyl ketene acetals derived from 0-alkyl acetates uni...

In this study, immobilized CuAlO2 onto the ZSM-12&35 composite was prepared and used as a photocatalyst to remove N-containing oil pollutants (Carbazole) through advanced oxidation. In this method, acetone is used as a reaction solvent that can be partially converted to fuel oxygenates compounds (Octane enhancers) through an aldol condensation reaction. Photocatalyst characterization was perfor...

The first example of a direct aldehyde–ketone coupling using the secondary amine piperidine as base in the presence of MgI2 to generate high selectivity of anti-aldol products from unmodified ethyl ketones in high yield is reported. The coupling reactions were carried out in a one-pot reaction by mixing four reaction components at room temperature. In the case of unsymmetrical ketones, addition...

The presence of a p-nitrophenyl group converts acetone into an excellent and versatile nucleophile in organocatalytic processes, able to react with α,β-unsaturated aldehydes affording β-substituted α-arylcyclohexenones via a Michael reaction/aldol reaction/dehydration sequence, which occurs in good yields, ee up to 96% and complete diastereoselectivity. The resulting compounds are excellent syn...

[reaction: see text] Three asymmetric pathways to the kavalactones have been developed. The first method is chiral auxiliary-based and utilizes aldol reactions of N-acetyl thiazolidinethiones followed by a malonate displacement/decarboxylation reaction. The second approach uses the asymmetric catalytic Mukaiyama additions of dienolate nucleophile equivalents developed by Carreira and Sato. Fina...

In the silyl Lewis acid-promoted Mukaiyama aldol reaction, the steric and electronic properties of the silyl group on the silyl Lewis acid influence the reaction mechanism and product distribution. When super silyl triflates such as (TMS)3SiOTf and (TES)3SiOTf are used as Lewis acids, the silyl group of the silyl enol ether chemoselectively transfers to the product. The mechanistic details have...

We have reported the fabrication of boric acid incorporated into surface of magnetite nanoparticles. The catalyst was characterized using spectroscopic, magnetic and thermal techniques (FT-IR, SEM, XRD, ICP, VSM and TGA). It catalyzed Mukaiyama aldol reaction of a ketene silyl acetal type nucleophile ((1-methoxy-2-methylprop-1-enyloxy) trimethylsilane), and various aldehydes (aromatic, aliphati...

Reported herein is a light-triggered organocatalytic strategy for the desymmetrization of achiral 2-fluoro-substituted cyclopentane-1,3-diketones. The chemistry is based on an intermolecular aldol reaction of photochemically generated hydroxy-o-quinodimethanes and simultaneously forges two adjacent fully substituted carbon stereocenters, with one bearing a stereogenic carbon-fluorine unit. The ...