elektrofilin

Elektrofilin is a term used in chemistry, primarily in German-language literature, that corresponds to what is commonly called an electrophile in English. An elektrofilin is a chemical species that seeks electrons and accepts electron density from a nucleophile to form a chemical bond. In Lewis theory terms, it is an electron-pair acceptor, often a positively charged ion or a polarizable molecule.

Electrofilins are typically electron-poor and are attracted to electron-rich centers such as double bonds, lone pairs, or negatively charged sites. Common examples include carbocations (for example, R3C+), the nitronium ion NO2+, protonated carbonyls, and Lewis acids like boron trifluoride BF3. In many reactions, elektrofilins react with nucleophiles such as alkenes, arenes, enolates, or halide ions to form new bonds. The reactivity of elektrofilins is described in part by the hard-soft acid-base (HSAB) concept, which distinguishes hard from soft elektrofilins and helps predict matching nucleophiles.

In organic synthesis, elektrofilins participate in key reaction classes such as electrophilic aromatic substitution, electrophilic addition to alkenes, and various acylation or alkylation processes. The choice of solvent, temperature, and accompanying counterions can influence the strength and selectivity of elektrofilin-induced transformations.

See also: electrophile, electrophilic substitution, Lewis acid, HSAB theory.