For questions about reactions that favour the formation of one or more stereoisomers.

Stereoselectivity is defined in the IUPAC Gold Book as "the preferential formation in a chemical reaction of one stereoisomer over another".

Stereoselective reactions can generally be categorised into two types:

  • enantioselective reactions, i.e. reactions that give rise to an unequal mixture of enantiomers. An example is the Sharpless asymmetric epoxidation:

    Sharpless epoxidation (JACS 1980 102 5974)

  • diastereoselective reactions, i.e. reactions that give rise to an unequal mixture of diastereomers. An example is olefin metathesis:

    Olefin metathesis (JACS 2003 125 11360)