oxidative addition

The insertion of a metal complex into a covalent bond involving formally an overall two-electron loss on one metal or a one-electron loss on each of two metals, i.e.
L n M m + XY → L n M m + 2 X Y,
or
2 L n M m + XY → L n M m + 1 X + L n M m + 1 Y
In radical chemistry, the term is used to indicate a radical addition to a carbon–carbon double bond, under oxidative conditions. For example:
O04367-2
Source:
PAC, 1994, 66, 1077 (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1149