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Catalytic asymmetric C–C cross-couplings enabled by photoexcitation


Enantioselective catalytic processes are promoted by chiral catalysts that can execute a specific mode of catalytic reactivity, channeling the chemical reaction through a certain mechanistic pathway. Here, we show how by simply using visible light we can divert the established ionic reactivity of a chiral allyl–iridium(iii) complex to switch on completely new catalytic functions, enabling mechanistically unrelated radical-based enantioselective pathways. Photoexcitation provides the chiral organometallic intermediate with the ability to activate substrates via an electron-transfer manifold. This redox event unlocks an otherwise inaccessible cross-coupling mechanism, since the resulting iridium(ii) centre can intercept the generated radicals and undergo a reductive elimination to forge a stereogenic centre with high stereoselectivity. This photochemical strategy enables difficult-to-realize enantioselective alkyl–alkyl cross-coupling reactions between allylic alcohols and readily available radical precursors, which are not achievable under thermal activation.

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Fig. 1: Enhancing the potential of generic modes of catalytic reactivity with light.
Fig. 2: Characterization and light-induced catalytic activity of the (η3-allyl)iridium(iii) complex Ir-1.
Fig. 3: Mechanistic considerations.

Data availability

The data that support the findings of this study are available in the Supplementary Information (experimental procedures and characterization data). Crystallographic data for the structures reported in this article have been deposited at the Cambridge Crystallographic Data Centre, under deposition numbers CCDC 2021458 (4g) and 2021459 (4h). Copies of the data can be obtained free of charge via


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This work is dedicated to the memory of Professor Kilian Muñiz. Financial support was provided by Agencia Estatal de Investigación (PID2019-106278GB-I00 and CTQ2016-75520-P), the AGAUR (Grant 2017 SGR 981) and the European Research Council (ERC-2015-CoG 681840-CATA-LUX). G.E.M.C. thanks the EU for a Horizon 2020 Marie Skłodowska-Curie Fellowship (H2020-MSCA-IF-2017, 795793). D.M. thanks H2020-MSCA-ITN-2016 (722591–PHOTOTRAIN) for a predoctoral fellowship. We thank A. Llobet and J. Holub for assistance with differential pulse voltammetry and E. E. Adán for help with X-ray crystallographic analysis.

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Authors and Affiliations



G.E.M.C. and P.M. conceived and supervised the project. G.E.M.C., A.F., E.G. and D.M. performed all experiments. All authors contributed to the experimental design and the interpretation of data. G.E.M.C. and P.M. directed the research and wrote the manuscript with input from all authors.

Corresponding author

Correspondence to Paolo Melchiorre.

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The authors declare no competing interests.

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Peer review information Nature Chemistry thanks the anonymous reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–24, Discussion, Tables 1 and 2, characterization of products, HPLC traces and 1H NMR and 13C NMR spectra.

Supplementary Data 1

Crystallographic data for compound 4g. CCDC 2021458.

Supplementary Data 2

Crystallographic data for compound 4h. CCDC 2021459.

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Crisenza, G.E.M., Faraone, A., Gandolfo, E. et al. Catalytic asymmetric C–C cross-couplings enabled by photoexcitation. Nat. Chem. 13, 575–580 (2021).

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