Nuovi N-ossidi chirali quali catalizzatori organici per l'allilazione stereoselettiva di aldeidi aromatiche

In the context of a rapidly growing interest in enantioselective organic (i.e. metal-free) catalysis, catalytic amounts of often structurally complex pyridine and amine N-oxides have been recently used by some research groups as organic Lewis bases capable of promoting the enantioselective allylation of aldehydes. In this thesis a research work aimed to develop simpler and easier-to-prepare chiral N-oxides is described. Three new families of chiral pyridine and amine N-oxides were synthesized and tested in the reaction of aromatic aldehydes with allyltrichlorosilane affording the corresponding homoallylic alcohols: * 2-picolinic and 2,6-pyridinedicarboxylic acid derivatives, prepared in one or two steps from cheap and commercially available starting products (up to 50% e.e. in the allylation of benzaldehyde); * 2-(2,6-dihydroxyphenyl)-3-methylpyridine derivatives, obtained by an efficient four-steps synthesis from commercially available products (up to 84% e.e. in the allylation of benzaldehyde); * trans-2,5-diphenylpyrrolidine derivatives, synthesized from 1,4-diphenylbutane-1,4-dione, whose development is still in progress.