comproportionation

https://doi.org/10.1351/goldbook.C01217
The reverse of disproportionation. The term 'symproportionation' is also used.
Source:
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1098 (https://doi.org/10.1351/pac199466051077)