# CPhos

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/CPhos
> Markdown URL: https://mediated.wiki/source/CPhos.md
> Source: https://en.wikipedia.org/wiki/CPhos
> Source revision: 1289186474
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

**CPhos** is a [phosphine ligand](/source/Phosphine_ligand) derived from [biphenyl](/source/Biphenyl). It is a white solid that is soluble in organic solvents.

Its [palladium](/source/Palladium) complexes exhibit high activity for [Negishi coupling reactions](/source/Negishi_coupling) involving aryl bromides, chlorides and [triflates](/source/Triflate). CPhos mediated reactions performed with secondary (sp3) [alkylzinc](/source/Organozinc_compound) halides often give excellent yields, with low conversion to the frequently encountered primary substituted [by-products](/source/By-product).[1]

## Utility in Negishi Coupling

A simplified [scheme](/source/Reaction_mechanism) showing the reaction course of isopropylzinc bromide with an aryl halide is shown below. Processes leading to byproduct formation are highlighted in red.

[Oxidative addition](/source/Oxidative_addition) (1) of the aryl halide to the palladium-[ligand](/source/Ligand) complex followed by [transmetalation](/source/Transmetalation) (2) gives intermediate **B** which can undergo [reductive elimination](/source/Oxidative_addition) (3) to afford the desired isopropyl arene **C**. However, intermediate **B** can also undergo [β-hydride elimination](/source/Beta-Hydride_elimination) (4) to afford **D**, which can either [reductively eliminate](/source/Oxidative_addition) (3’) to afford de-halogenated product **G**, or undergo [insertion](/source/Insertion_reaction) (5) leading to the formation of **E**. Once formed, **E** may also undergo [reductive elimination](/source/Oxidative_addition) (3’’) to afford the *n*-propyl by-product **F**.

CPhos minimises the conversion to undesired products **F** & **G** by increasing the rate of the [reductive elimination](/source/Oxidative_addition) of **B**, relative to the rate of [β-hydride elimination](/source/Beta-Hydride_elimination).

## See also

- [Negishi coupling](/source/Negishi_coupling)
- [XPhos](/source/XPhos)
- [SPhos](/source/SPhos)
- [Dialkylbiaryl phosphine ligands](/source/Dialkylbiaryl_phosphine_ligands)

## References

1. Han, C. & Buchwald, S. L. (2009). "Negishi Coupling of Secondary Alkylzinc Halides with Aryl Bromides and Chlorides". *[J. Am. Chem. Soc.](/source/J._Am._Chem._Soc.)*. **131** (22): 7532–7533. [doi:10.1021/ja902046m](https://doi.org/10.1021/ja902046m). [PMC 2746668](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2746668). [PMID 19441851](https://pubmed.ncbi.nlm.nih.gov/19441851)

## External links

- [CPhos at Sigma Aldrich](http://www.sigmaaldrich.com/catalog/product/aldrich/759171?lang=en&region=GB/)
- [CPhos Pd G2 (precatalyst) at Sigma Aldrich](http://www.sigmaaldrich.com/catalog/product/aldrich/763012?lang=en&region=GB/)
- [CPhos Pd G3 (precatalyst) at Sigma Aldrich](http://www.sigmaaldrich.com/catalog/product/aldrich/763004?lang=en&region=GB/)

---
Adapted from the Wikipedia article [CPhos](https://en.wikipedia.org/wiki/CPhos) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/CPhos?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.