Our interest in gold catalysis1 prompted us to explore the challenging task of activation of CAr−X bonds, which remains highly elusive for AuI complexes. Contrary to ML2 complexes of Pd0 metal, linear ML2 AuI complexes [LAuX] and [L2Au+] are highly stable and reluctant to undergo oxidative addition. Recently, Joost et al. reported the first AuI complex undergoing oxidative addition of aryl iodides, highlighting the bent angle L-AuI-L as key for the observed reactivity (Scheme 1a).2 Despite that, the physical factors controlling this fundamental process are not completely understood so far. To this end, our DFT calculations aimed at a deeper understanding of those factors controlling the oxidative addition of PhCl to mono ligated AuI-L, Pd0-L complexes (L=PMe3, PPh3, and NHC), and bis-ligated L-AuI-L, L-Pd0-L (L= PMe3 and NHC) linear and bent complexes (L=diphosphines and bis-NHC). As expected, our results suggest that the oxidative addition of PhCl to Pd0-L complexes is thermodynamically favorable and kinetically easier than for the corresponding AuI-L complexes. Further, for linear L-Pd0-L complexes, the activation event is slightly kinetically demanding than for the corresponding Pd0-L complexes, but in both cases the final product is thermodynamically favorable. Consistent with AuI-L complexes, linear L-AuI-L complexes present an unfavorable reaction profile for the oxidative addition of PhCl. However, for the bent L-AuI-L complexes, the oxidative addition of PhCl is kinetically facile and the oxidative addition product is clearly more stable than the reactants, which is a remarkable difference form the corresponding linear L-Au1-L complexes (Scheme 1b). In this contribution we focus on a rationalization of the peculiar behavior of AuI complexes through their comparison with the isoelectronic Pd0 complexes. References (a) Vummaleti, S. V. C.; Falivene, L.; Poater, A.; Cavallo, L. ACS Catal. 2014, 4, 1287-1291. (b) Gómez-Suárez, A.; Gasperini, D.; Vummaleti, S. V. C.; Poater, A.; Cavallo, L.; Nolan, S. P. ACS Catal. 2014, 4, 2701-2705. Joost, M.; Zeineddine, A.; Estevez, L.; Mallet-Ladeira, S.; Miqueu, K.; Amgoune, A.; Bourissou, D. J. Am. Chem. Soc. 2014, 136, 14654 – 14657.

Oxidative addition of aryl chloride to mono ligated and bi-ligated linear/bent AuI and Pd0 complexes

250th National Meeting (2015)

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