Search

A new preparative route to aryl-substituted derivatives of the linear-orthogonal 2-azaalenium ions (2-azoniaalene ions) is reported. X-ray, IR, and NMR data was used to obtain complete structural information about the products obtained. The results are compared with high level ab initio and density functional theory calculations.

A furan-derived sulfone reacts with 1 equivalent of sodium bis(2-methoxyethoxy)aluminum dihydride to form a bicyclic compound, substituted cyclohexanols. This reaction involves an elimination step and an alkoxide-influenced remote conjugate hydride addition. Organolithium reagents react with sulfone to give alkylated products that involve a tandem elimination/1,6 addition. The reaction proves the mechanism of the formation of the bicyclic compound.

Evidence is presented for the possible involvement of betaine-type structures in the thio-Wittig reaction of the ylides Ph3P=*CH2 and triethylethylidenephosphorane. The occurrence of a betaine-type structure is strongly influenced by electronic effects. A transition between thiaphosphetane- and gauche-betaine-type structures of the intermediates involved seems to occur depending on the reaction conditions and the electronic features.

A novel organometallic template reduction was used to form stable cyclopropenylium betaine. The synthesis used the combined action of a group 4 transition metal and a highly Lewis-acidic boron center to avoid the kinetic and thermodynamivc restraints of methylenecyclopropene formation by means of dimerization of two acetylenic units. Results indicate that the proposed approach is capable of producing neutral compounds with pronounced cyclopropeneylium betaine character.