Dynamic control of chirality in phosphine ligands for enantioselective catalysis

• Published in: Nature communications 2015-03, Vol.6 (1), p.6652-6652, Article 6652
• Main Authors: Zhao, Depeng, Neubauer, Thomas M., Feringa, Ben L.
• Format: Article
• Language: English
• Subjects: 140/131; 639/638/263/406/77/883; 639/638/403/935; 639/638/439; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms7652

Chirality plays a fundamental role in biology and chemistry and the precise control of chirality in a catalytic conversion is a key to modern synthesis most prominently seen in the production of pharmaceuticals. In enantioselective metal-based catalysis, access to each product enantiomer is commonly achieved through ligand design with chiral bisphosphines being widely applied as privileged ligands. Switchable phosphine ligands, in which chirality is modulated through an external trigger signal, might offer attractive possibilities to change enantioselectivity in a catalytic process in a non-invasive manner avoiding renewed ligand synthesis. Here we demonstrate that a photoswitchable chiral bisphosphine based on a unidirectional light-driven molecular motor, can be used to invert the stereoselectivity of a palladium-catalysed asymmetric transformation. It is shown that light-induced changes in geometry and helicity of the switchable ligand enable excellent selectivity towards the racemic or individual enantiomers of the product in a Pd-catalysed desymmetrization reaction. Typically in asymmetric catalysis each product enantiomer is produced using a different enantiomer of catalyst. Here, the authors show a photoswitchable bisphosphine ligand, capable of altering the stereoselectivity of a palladium catalysed process and producing either enantiomer of product.