##  [Reductive Elimination](/reductive-elimination-0) 

 Definition

An organometallic elementary step in which two ligands bound to a metal center couple to form a covalent bond and are released as a neutral or ionic product, reducing the metal’s formal oxidation state and often decreasing coordination number.

 

 

 

 

 

 





## Principle

Principle

Requires proximal and often cis‑configured ligands on a higher‑valent metal and an electronic environment that allows two‑electron bond formation between ligands; steric and electronic factors control the facility and selectivity of elimination.

 

 

 

 

 





## Demonstration

Demonstration

Reductive elimination from a Pd(II) diaryl complex: two aryl ligands on palladium couple to form a biaryl product and regenerate a Pd(0) species, a key step in cross‑coupling catalysis.

 

 

 

 

## Misapplication

Misapplication

Describing simple dissociative ligand loss (where a ligand leaves without coupling) or outer‑sphere nucleophilic attack on a ligand as reductive elimination; conflating single‑electron pathways that change oxidation state with concerted two‑electron eliminations.

 

 

 

 

 





## Consequence

Consequence

Product formation that closes catalytic cycles and regenerates a lower‑valent active metal species; control of reductive elimination determines turnover and selectivity in many bond‑forming catalytic reactions.

 

 

 

 

## Reversal

Reversal

Oxidative addition is the microscopic reverse operation, wherein the low‑valent metal forms two new bonds to fragments and increases its oxidation state.

 

 

 

 

 





## Boundary

Boundary

Pertains to two‑electron coupling and release of ligands from a metal center; excludes heterolytic ligand dissociation without coupling, redox events mediated by ligand noninnocence, and stepwise radical couplings not involving concerted two‑electron metal‑center processes.

 

 

 

 

 





## Semantic Tension

Semantic Tension

Often confused with simple ligand dissociation or outer‑sphere substitution; mechanistically, reductive elimination implies internal coupling and electron flow that are distinct from dissociative or purely nucleophilic transformations.

 

 

 

 

 





## Synthesis

Synthesis

An internal two‑electron coupling of two ligands on a higher‑valent metal to form a new bond and depart, lowering the metal’s formal oxidation state and often regenerating the catalytically active species.