Sulfoxides in the allylation of aldehydesin the presence of silicon tetrachlorideand allyltributylstannane

SiCl4 can be conveniently activated by catalytic amounts of dimethyl sulfoxide or other readily-available sulfoxides for the allylation of aromatic, hetero-aromatic and unsaturated aldehydes in the presence of allyltributyl stannane. Chiral aryl methyl sulfoxides have been used to develop asymmetric allylation methods, as well as probe the aldehyde substrate scop

Mukaiyama-Michael vinylogous additions to nitroalkenes under solvent-free conditions

Abstract The first Mukaiyama-Michael vinylogous reaction of a dioxinone-derived silyl ether to nitroalkenes is reported. The conjugate addition is performed in absence of any catalyst under solvent-free conditions, proceeding with satisfactory efficiency with variously substituted nitroalkenes. Moreover, the first organocatalyzed Mukaiyama-Michael vinylogous reaction of trimethylsilyloxyfuran to nitroalkenes is described.The reaction is promoted by Brønsted acids under solvent-free conditions, taking place in moderate to good yield with variously substituted nitroalkenes.

A re-investigation of Modena’s protocol for the asymmetric oxidation of prochiral sulfides

The reactivity of commercially available or easily accessible hydroperoxides has been conveniently exploited for the achievement of highly efficient and enantioselective catalytic modifications of Modenas protocol for the asymmetric oxidation of sulfides. A notably enhanced enantioselectivity has been obtained by exploiting a concomitant process of stereoconvergent kinetic resolution taking place under catalytic conditions

Chiral sulfoxides as activators of allyl trichlorosilanes in the stereoselective allylation of aldehydes

Chiral aryl methyl sulfoxides proved to be efficient activators in the asymmetric allylation of aldehydes with allyl trichlorosilanes. High enantioselectivity was found in the case of electron-poor aldehydes. The high levels of diastereoselectivity and the detection of nonlinear effects have allowed the elucidation of some mechanistic aspects of the reaction

1-Naphthyl-TADDOL/Emim BF4: A new catalytic system for the asymmetric addition of Chan's diene to aromatic aldehydes

AbstractA new organocatalytic system was tested as a promoter for the asymmetric addition of Chan's diene to aldehydes under solvent-free conditions. This new organocatalyst generated in situ by mixing 1-naphthyl-TADDOL derivative and Emim BF4 was able to give enantioenriched vinylogous aldols and hetero-Diels-Alder cycloadducts. A mechanistic investigation through the detection of nonlinear effects confirmed the involvement of the ionic liquid in the formation of a new catalytic supramolecular species

A catalytic asymmetric allylation of aldehydes with allyl trichlorosilane activated by a chiral tetradentate bis-sulfoxide

Chiral homoallylic alcohols are easily accessible by asymmetric allylation of aldehydes with allyl trichlorosilane in the presence of catalytic amounts of a chiral tetradentate bis-sulfoxide, as organocatalyst, whose synthesis is reported