Identification of carbonium and carbenium ions by QTAIM

Identification of Carbonium and Carbenium Ions by QTAIM

A ferramenta de Gassman-Fentiman da demanda crescente de elétrons foi usada para identificar íons carbênios e íons carbônios. Contudo, devido ao seu entendimento ambíguo, ela foi pivô de uma disputa histórica. Nós aplicamos a metodologia da Teoria Quântica de Átomos em Moléculas QTAIM para caracterizar íons carbênios e íons carbônios de uma forma mais eficaz e mais fácil. Essa metodologia pode ...

Carbenium and carbonium ions in liquid- and solid-superacid-catalyzed activation of small alkanes*

Acid-catalyzed hydrocarbon reactions involve by far the largest amount of catalyst and the largest volume of transformation in oil refinery and chemical industry. However, despite the general agreement on the carbocationic nature of the reaction intermediates, the initial steps and the true nature of the cations on the surface are still open to debate. On these points our basic knowledge has ga...

Production of carbenium ions from carbenes by protonation

Diphenyl-, aryl-a-siloxyand %-furany1 carbenes can be protonated by even weak proton donors such as alcohols (by a bimolecular or by a pre-association mechanism involving more than one alcohol molecule) to yield the corresponding carbenium ions, whose spectra and electrophilic patterns of behavior are described. INTRODUCTION Proton transfer reactions to and from heteroatoms (= "normal" Bronsted...

Extended Hückel Theory. IV. Carbonium Ions

Selenium Stabilized Carbenium Ions on Organic Synthesis

Organoselenium compounds have been known for a long time as versatile reagents in organic chemistry. In the last years there has been a considerable development of selenium-based methods for organic synthesis. Many of these methods are currrently been used as standard procedures to introduce new functional groups under mild conditions. From the several areas of interest in organoselenium chemis...