As Nice as π: Aromatic Reactions Activated by π‐Coordination to Transition Metals

• Published in: Chemistry : a European journal Vol. 27; no. 11; pp. 3650 - 3660
• Main Authors: Williams, Luke J., Bhonoah, Yunas, Wilkinson, Luke A., Walton, James W.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 19.02.2021; John Wiley and Sons Inc
• Subjects: arene complexes; Aromatic compounds; catalysis; Chemistry; Coordination; coordination complexes; Metals; Minireview; Minireviews; Stereoselectivity; Transition metals; catalysis; coordination complexes; arene complexes; transition metals
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202004621

π‐Coordination of aromatic molecules to metals dramatically alters their reactivity. For example, coordinated carbons become more electrophilic and C−H bonds of coordinated rings become more acidic. For many years, this change in reactivity has been used to trigger reactions that would not take place for uncoordinated arenes, however, there has been a recent resurgence in use of this technique, in part due to the development of catalytic reactions in which π‐coordination is transient. In this Minireview, we describe the key reaction chemistry of arenes coordinated to a range of transition metals, including stereoselective reactions and industrially relevant syntheses. We also summarise outstanding examples of catalytic processes. Finally, we give perspectives on the future direction of the field, with respect to both reactions that are stoichiometric in activating metals and those employing catalytic metal. Easy as π: π‐Coordination of aromatic compounds to transition metals dramatically alters the reactivity of the arene. In this Minireview, the authors highlight reactions that exploit this increased activity, selecting examples that are both stoichiometric and catalytic in the activating metal. The advantages and limitations of the activation strategy are discussed and it is considered which areas of future research will benefit from this technique.