SN2tyyppisellä

SN2tyyppisellä is a Finnish term that translates to "SN2-type" or "SN2-like" in English. It refers to a reaction mechanism commonly encountered in organic chemistry, specifically nucleophilic substitution. The SN2 designation stands for Bimolecular Nucleophilic Substitution. This means that the rate of the reaction depends on the concentration of both the nucleophile and the substrate.

In an SN2 reaction, a nucleophile attacks an electrophilic carbon atom from the backside, simultaneously displacing a leaving group. This occurs in a single, concerted step, meaning bond breaking and bond formation happen at the same time. A key characteristic of SN2 reactions is the inversion of stereochemistry at the carbon atom undergoing substitution. If the carbon is chiral, the configuration will be flipped after the reaction. Steric hindrance around the electrophilic carbon can significantly slow down or prevent SN2 reactions, as bulky groups can impede the nucleophile's approach. Primary and methyl halides are generally the most reactive substrates in SN2 reactions, followed by secondary halides. Tertiary halides typically do not undergo SN2 reactions due to excessive steric hindrance. The SN2 mechanism is a fundamental concept for understanding the reactivity of many organic molecules.