Dr. Myers Organic Chemistry Courses at Ohio Northern University
My all-time favorite chemical reaction has to be the S N 2. This may sound like a cop-out answer to Rachel Pepling’s question , since the S N 2 is arguably the second* simplest organic reaction ever, almost more a mechanistic step than a reaction per se .
However, its simplicity is deceiving. Our old familiar S N 2 reaction is an absolute treasure trove of organic chemistry principles. The details of this reaction exquisitely illustrate nucleophilicity/electrophilicity, stereochemistry, sterics, kinetics, solvent effects, and so very much more. There are ritzy versions of the S N 2 (e.g., Mitsunobu) for those of us that want a little extra sophistication. The S N 2 can even cure – or cause – cancer (DNA alkylation).
An Overview of S N 2 For anyone stumbling across this that hasn’t brushed up on organic chemistry in a while, an S N 2 reaction is a bimolecular nucleophilic substitution reaction. (The “S” and the “N” come from two of those words – I’ll let you guess which ones – and the “2” represents bi molecular). In general, a substitution reaction is one in which a little piece of a molecule falls off and gets replaced by another new piece. The piece that falls off is called a “leaving group” (shown in red below), and
Dr. Myers Organic Chemistry Courses at Ohio Northern University