Facile, Catalytic Dehydrocoupling of Phosphines Using β-Diketiminate Iron(II) Complexes

• Published in: Chemistry : a European journal Vol. 21; no. 45; pp. 15960 - 15963
• Main Authors: King, Andrew K., Buchard, Antoine, Mahon, Mary F., Webster, Ruth L.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 02.11.2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Alkenes; Catalysis; Catalysts; Chemistry; Coordination compounds; homogeneous catalysis; Iron; phosphanes; Phosphines; phosphorus; Radicals; Solvents; Switches; Transformations; iron; homogeneous catalysis; radicals; phosphanes; phosphorus
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201503399

Catalytic dehydrocoupling of primary and secondary phosphines has been achieved for the first time using an iron pre‐catalyst. The reaction proceeds under mild reaction conditions and is successful with a range of diarylphosphines. A proton acceptor is not needed for the transformation to take place, but addition of 1‐hexene does allow for turnover at 50 °C. The catalytic system developed also facilitates the dehydrocoupling of phenylphosphane and dicyclohexylphosphane. A change in solvent switches off dehydrocoupling to allow hydrophosphination of alkenes. Fe, Fi, Fo, phosphorus! Use of iron(II) β‐diketiminate complexes leads to the dehydrocoupling (DHC) of phosphines. Preliminary mechanistic studies reveal that a radical mechanism is operating, whereas a change in solvent results in a vast change in reactivity, switching off DHC and allowing hydrophosphination to take place.