A regioselective reaction is one in which one direction of bond making or breaking
occurs preferentially over all other possible directions. Reactions are termed completely
(100%) regioselective if the discrimination is complete, or partially (
x%), if the product of reaction at one site predominates over the product of reaction
at other sites. The discrimination may also semi-quantitatively be referred to as
high or low regioselectivity. (Originally the term was restricted to
addition reactions of unsymmetrical reagents to unsymmetrical
alkenes.) In the past, the term '
regiospecificity' was proposed for 100% regioselectivity. This terminology is not recommended owing
to inconsistency with the terms
stereoselectivity and
stereospecificity.
Source:
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1160
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.
