Samarium(II) iodide is a strong one-electron transfer reducing agent, and is effective for the cyclo- and hydrodimerization of cyclic and non-cyclic α,β-unsaturated ketones. The title dimers can easily be prepared in good yields at room temperature under neutral conditions, using two-mole equivalent of SmI₂ per mole of starting substrate. The reaction is stereocontrolled. The absence of an alcohol as a proton source is essential in the process and the use of HMPA as a copromoter improves the yield of dimeric products, making the reaction regioselective over the competitive CC double bond reduction. The crystal structures of some of the dimeric derivatives are reported. When η²- or η⁴-iron-coordinated α,β-unsaturated ketones are used as substrates, the reaction gives mainly the 1,4-reduced products.

The reactivity of both natural montmorillonite and montmorillonite modified with super acids (CF₃SO₃H and HClO₄) to generate hydrogen peroxide (H₂O₂) and hydroxyl radicals (˙OH) under both darkness and UV-light irradiation was investigated using EPR spin-trapping spectroscopy. We used the free-radical trapping action of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) to indicate the production of ˙OH from natural and modified clays. The recognition and characterisation of the formed DMPO–OH adduct established that super acid montmorillonites were able to generate hydroxyl radicals at 25 °C in the presence of O₂ and H₂O. When natural and acid montmorillonite were irradiated with UV light, hydroxyl radical generation was greater than under dark conditions. In addition, the peroxidation of lipids in biological matrices with natural and super acid montmorillonite was studied using a thiobarbituric acid reactive substances (TBARS) assay, which demonstrated that only ˙OH generated from the super acid montmorillonite induced the oxidative degradation of lipids. This study reports, for the first time, the generation of ˙OH and the peroxidation of lipids by a typical super acid-modified Mexican montmorillonite.

Three homoisoflavanones were isolated from the “piña” and leaves of Agave tequilana Weber. The compounds were identified as: 5,7-dihydroxy-3-(4-methoxybenzyl)-chroman-4-one (1), 7-hydroxy-3-(4-hydroxybenzyl)-chroman-4-one (2) and 4’-demethyl-3,9-dihydro-punctatin (3). This is the first phytochemical study carried out to Agave tequilana Weber.

A number of Aldo, Keto and O-Acetyl oximes have been deblocked using chemisorbed Chromyl chloride on Bentonite and Silica Gel. A comparative study between the Chromyl chloride in solution and supported is also given.

Tonsil Actisil FF, which is a commercial bentonitic clay, promotes the formation of cycloveratrylene macrocycles and benzyl oligomers from the corresponding benzyl alcohols in good yields under microwave heating and infrared irradiation in the absence of solvent in both cases. The catalytic reaction is sensitive to the type of substituent on the aromatic ring. Thus, when benzyl alcohol was substituted with a methylenedioxy, two methoxy or three methoxy groups, a cyclooligomerisation process was induced. Unsubstituted, methyl and methoxy benzyl alcohols yielded linear oligomers. In addition, computational chemistry calculations were performed to establish a validated mechanistic pathway to explain the growth of the obtained linear oligomers.