Abstract
Organocatalysis—catalysis mediated by small chiral organic molecules—is a powerful technology for enantioselective synthesis, and has extensive applications in traditional ionic, two-electron-pair reactivity domains. Recently, organocatalysis has been successfully combined with photochemical reactivity to unlock previously inaccessible reaction pathways, thereby creating new synthetic opportunities. Here we describe the historical context, scientific reasoning and landmark discoveries that were essential in expanding the functions of organocatalysis to include one-electron-mediated chemistry and excited-state reactivity.
This is a preview of subscription content, access via your institution
Relevant articles
Open Access articles citing this article.
-
Red light-driven electron sacrificial agents-free photoreduction of inert aryl halides via triplet-triplet annihilation
Nature Communications Open Access 27 February 2023
-
Visible-light mediated catalytic asymmetric radical deuteration at non-benzylic positions
Nature Communications Open Access 01 August 2022
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Get just this article for as long as you need it
$39.95
Prices may be subject to local taxes which are calculated during checkout





References
Dalko, P. I. (ed.) Comprehensive Enantioselective Organocatalysis: Catalysts, Reactions, and Applications (Wiley-VCH, 2013)
Ojima, I. (ed.) Catalytic Asymmetric Synthesis (John Wiley & Sons, 2010)
Eder, U., Sauer, G. & Wiechert, R. New type of asymmetric cyclization to optically active steroid CD partial structures. Angew. Chem. Int. Ed. Engl. 10, 496–497 (1971)
Hajos, Z. G. & Parrish, D. R. Asymmetric synthesis of bicyclic intermediates of natural product chemistry. J. Org. Chem. 39, 1615–1621 (1974)
Hiemstra, H. & Wynberg, H. Addition of aromatic thiols to conjugated cycloalkenones, catalyzed by chiral β-hydroxy amines. A mechanistic study of homogeneous catalytic asymmetric synthesis. J. Am. Chem. Soc. 103, 417–430 (1981)
Dolling, U. H., Davis, P. & Grabowski, E. J. J. Efficient catalytic asymmetric alkylations. 1. Enantioselective synthesis of (+)-indacrinone via chiral phase-transfer catalysis. J. Am. Chem. Soc. 106, 446–447 (1984)
List, B., Lerner, R. A. & Barbas, C. F., III . Proline-catalyzed direct asymmetric aldol reactions. J. Am. Chem. Soc. 122, 2395–2396 (2000)
Ahrendt, K. A ., Borths, C. J . & MacMillan, D. W. C. New strategies for organic synthesis: the first highly enantioselective organocatalytic Diels-Alder reaction. J. Am. Chem. Soc. 122, 4243–4244 (2000). Refs 7 and 8 document the seminal studies on enamine- and iminium-ion-mediated catalysis, respectively, which established the field of modern organocatalysis
MacMillan, D. W. C. The advent and development of organocatalysis. Nature 455, 304–308 (2008). Thought-provoking discussion on the reasons behind the sudden growth in the field of modern organocatalysis
Grondal, C., Jeanty, M. & Enders, D. Organocatalytic cascade reactions as a new tool in total synthesis. Nat. Chem. 2, 167–178 (2010)
Jones, S. B., Simmons, B., Mastracchio, A. & MacMillan, D. W. C. Collective synthesis of natural products by means of organocascade catalysis. Nature 475, 183–188 (2011)
Albini, A. & Fagnoni, M. (eds) Handbook of Synthetic Photochemistry (Wiley-VCH, 2010)
Schultz, D. M. & Yoon, T. P. Solar synthesis: prospects in visible light photocatalysis. Science 343, 1239176 (2014)
Chatgilialoglu, C. & Studer, A. (eds) Encyclopedia of Radicals in Chemistry, Biology and Materials (Wiley-VCH, 2014)
Brimioulle, R., Lenhart, D., Maturi, M. M. & Bach, T. Enantioselective catalysis of photochemical reactions. Angew. Chem. Int. Ed. 54, 3872–3890 (2015). Insightful review of the general strategies and concepts underlying the implementation of photochemical homogenous catalytic enantioselective processes
Sibi, M. P., Manyem, S. & Zimmerman, J. Enantioselective radical processes. Chem. Rev. 103, 3263–3296 (2003)
Shaw, M. H., Twilton, J. & MacMillan, D. W. C. Photoredox catalysis in organic chemistry. J. Org. Chem. 81, 6898–6926 (2016)
Melchiorre, P. Light in aminocatalysis: the asymmetric intermolecular α-alkylation of aldehydes. Angew. Chem. Int. Ed. 48, 1360–1363 (2009)
Ireland, R. E. Organic Synthesis (Prentice-Hall, 1969)
Evans, D. A. in Asymmetric Synthesis Vol. 3, Part B (ed. Morrison, J. D.) Ch. 1, 1–110 (Academic, 1983)
Doyle, A. G. & Jacobsen, E. N. Enantioselective alkylations of tributyltin enolates catalyzed by Cr(salen)Cl: access to enantiomerically enriched all-carbon quaternary centers. J. Am. Chem. Soc. 127, 62–63 (2005)
Dai, X., Strotman, N. A. & Fu, G. C. Catalytic asymmetric Hiyama cross-couplings of racemic α-bromo esters. J. Am. Chem. Soc. 130, 3302–3303 (2008)
Stork, G., Brizzolara, A., Landesman, H., Szmuszkovicz, J. & Terrell, R. The enamine alkylation and acylation of carbonyl compounds. J. Am. Chem. Soc. 85, 207–222 (1963)
List, B. et al. The catalytic asymmetric α-benzylation of aldehydes. Angew. Chem. Int. Ed. 53, 282–285 (2014)
Nicewicz, D. A. & MacMillan, D. W. C. Merging photoredox catalysis with organocatalysis: the direct asymmetric alkylation of aldehydes. Science 322, 77–80 (2008). Besides providing a solution for the longstanding problem of the direct catalytic asymmetric α-alkylation of aldehydes, this seminal study demonstrated the great potential of combining photoredox and organocatalysis
Giese, B. Radicals in Organic Synthesis: Formation of Carbon–Carbon Bonds (Pergamon, 1986)
Juris, A. et al. Ru(ii) polypyridine complexes: photophysics, photochemistry, electrochemistry, and chemiluminescence. Coord. Chem. Rev. 84, 85–277 (1988)
van Bergen, T. J., Hedstrand, D. M., Kruizinga, W. H. & Kellogg, R. M. Chemistry of dihydropyridine. 9. Hydride transfer from 1,4-dihydropyridine to sp3-hybridized carbon in sulfonium salts and activated halides. Studies with NAD(P)H models. J. Org. Chem. 44, 4953–4962 (1979)
Cismesia, M. A. & Yoon, T. P. Characterizing chain processes in visible light photoredox catalysis. Chem. Sci. 6, 5426–5434 (2015); erratum 6, 6019 (2015). Early demonstration of the importance of applying classical experimental techniques, most relevant to photophysical investigations, for elucidating the mechanism of photoredox organocatalytic processes
Neumann, M., Füldner, S., König, B. & Zeitler, K. Metal-free, cooperative asymmetric organophotoredox catalysis with visible light. Angew. Chem. Int. Ed. 50, 951–954 (2011)
Gualandi, A. et al. Organocatalytic enantioselective alkylation of aldehydes with [Fe(bpy)3]Br2 catalyst and visible light. ACS Catal. 5, 5927–5931 (2015)
Nagib, D. A., Scott, M. E. & MacMillan, D. W. C. Enantioselective α-trifluoromethylation of aldehydes via photoredox organocatalysis. J. Am. Chem. Soc. 131, 10875–10877 (2009)
Shih, H.-W., Vander Wal, M. N., Grange, R. L. & MacMillan, D. W. C. Enantioselective α-benzylation of aldehydes via photoredox organocatalysis. J. Am. Chem. Soc. 132, 13600–13603 (2010)
Welin, E. R., Warkentin, A. A., Conrad, J. C. & MacMillan, D. W. C. Enantioselective α-alkylation of aldehydes by photoredox organocatalysis: rapid access to pharmacophore fragments from β-cyanoaldehydes. Angew. Chem. Int. Ed. 54, 9668–9672 (2015)
Zhu, Y., Zhang, L. & Luo, S. Asymmetric α-photoalkylation of β-ketocarbonyls by primary amine catalysis: facile access to acyclic all-carbon quaternary stereocenters. J. Am. Chem. Soc. 136, 14642–14645 (2014)
Ischay, M. A., Anzovino, M. E., Du, J. & Yoon, T. P. Efficient visible light photocatalysis of [2 + 2] enone cycloadditions. J. Am. Chem. Soc. 130, 12886–12887 (2008)
Narayanam, J. M. R., Tucker, J. W. & Stephenson, C. R. J. Electron-transfer photoredox catalysis: development of a tin-free reductive dehalogenation reaction. J. Am. Chem. Soc. 131, 8756–8757 (2009)
Twilton, J., Le, C., Zhang, P., Shaw, M. H., Evans, R. W. & MacMillan, D. W. C. The merger of transition metal and photocatalysis. Nat. Rev. Chem. 1, 0052 (2017)
Yoon, T. P. Photochemical stereocontrol using tandem photoredox–chiral Lewis acid catalysis. Acc. Chem. Res. 49, 2307–2315 (2016)
Beeson, T. D., Mastracchio, A., Hong, J.-B., Ashton, K. & Macmillan, D. W. C. Enantioselective organocatalysis using SOMO activation. Science 316, 582–585 (2007). Early use of organocatalysis in enantioselective radical chemistry, before the advent of photoredox catalysis
Koike, T. & Akita, M. Photoinduced oxyamination of enamines and aldehydes with TEMPO catalyzed by [Ru(bpy)3]2+. Chem. Lett. 38, 166–167 (2009)
Capacci, A. G., Malinowski, J. T., McAlpine, N. J., Kuhne, J. & MacMillan, D. W. C. Direct, enantioselective α-alkylation of aldehydes using simple olefins. Nat. Chem. 9, 1073–1077 (2017)
Flamigni, L., Barbieri, A., Sabatini, C., Ventura, B. & Barigelletti, F. in Photochemistry and Photophysics of Coordination Compounds II (eds Balzani, V. & Campagna, S. ) 143–203 (Springer, 2007)
Mayer, J. M. Understanding hydrogen atom transfer: from bond strengths to Marcus theory. Acc. Chem. Res. 44, 36–46 (2011)
Pirnot, M. T., Rankic, D. A., Martin, D. B. C. & MacMillan, D. W. C. Photoredox activation for the direct b-arylation of ketones and aldehydes. Science 339, 1593–1596 (2013)
Studer, A. The persistent radical effect in organic synthesis. Chem. Eur. J. 7, 1159–1164 (2001)
Curran, D. P., Porter, N. A. & Giese, B. (eds) Stereochemistry of Radical Reactions (VCH Verlag, 1996)
Jakobsen, H. J., Lawesson, S. O., Marshall, J. T. B., Schroll, G. & Williams, D. H. Mass spectrometry. XII. Mass spectra of enamines. J. Chem. Soc. B 940–946 (1966)
Murphy, J. J., Bastida, D., Paria, S., Fagnoni, M. & Melchiorre, P. Asymmetric catalytic formation of quaternary carbons by iminium ion trapping of radicals. Nature 532, 218–222 (2016)
Bahamonde, A. et al. Studies on the enantioselective iminium ion trapping of radicals triggered by an electron-relay mechanism. J. Am. Chem. Soc. 139, 4559–4567 (2017)
Fischer, H. & Radom, L. Factors controlling the addition of carbon-centered radicals to alkenes—an experimental and theoretical perspective. Angew. Chem. Int. Ed. 40, 1340–1371 (2001)
Quasdorf, K. W. & Overman, L. E. Catalytic enantioselective synthesis of quaternary carbon stereocentres. Nature 516, 181–191 (2014)
DiRocco, D. A. & Rovis, T. Catalytic asymmetric α-acylation of tertiary amines mediated by a dual catalysis mode: N-heterocyclic carbene and photoredox catalysis. J. Am. Chem. Soc. 134, 8094–8097 (2012)
Bergonzini, G., Schindler, C. S., Wallentin, C.-J., Jacobsen, E. N. & Stephenson, C. R. J. Photoredox activation and anion binding catalysis in the dual catalytic enantioselective synthesis of β-amino esters. Chem. Sci. 5, 112–116 (2014)
Lian, M., Li, Z., Cai, Y., Meng, Q. & Gao, Z. Enantioselective photooxygenation of β-keto esters by chiral phase-transfer catalysis using molecular oxygen. Chem. Asian J. 7, 2019–2023 (2012)
Rono, L. J ., Yayla, H. G ., Wang, D. Y ., Armstrong, M. F. & Knowles, R. R. Enantioselective photoredox catalysis enabled by proton-coupled electron transfer: development of an asymmetric aza-pinacol cyclization. J. Am. Chem. Soc. 135, 17735–17738 (2013). Seminal example demonstrating the possibility of exploiting proton-coupled electron transfer in enantioselective organocatalysis
Miller, D. C., Tarantino, K. T. & Knowles, R. R. Proton-coupled electron transfer in organic synthesis: fundamentals, applications, and opportunities. Top. Curr. Chem. 374, 30 (2016)
Uraguchi, D., Kinoshita, N., Kizu, T. & Ooi, T. Synergistic catalysis of ionic Brønsted acid and photosensitizer for a redox neutral asymmetric α-coupling of N-arylaminomethanes with aldimines. J. Am. Chem. Soc. 137, 13768–13771 (2015)
Turro, N. J., Ramamurthy, V. & Scaiano, J. C. Modern Molecular Photochemistry of Organic Molecules (University Science Books, 2010)
Balzani, V . Ceroni, P. & Juris, A. Photochemistry and Photophysics (Wiley-VCH, 2014)
Arceo, E ., Jurberg, I. D ., Alvarez-Fernández, A . & Melchiorre, P. Photochemical activity of a key donor–acceptor complex can drive stereoselective catalytic α-alkylation of aldehydes. Nat. Chem. 5, 750–756 (2013). First demonstration that enamines—key intermediates in ground-state organocatalysis—can use photochemical mechanisms to activate substrates
Mulliken, R. S. Molecular compounds and their spectra. II. J. Am. Chem. Soc. 74, 811–824 (1952)
Rathore, R. & Kochi, J. K. Donor/acceptor organizations and the electron-transfer paradigm for organic reactivity. Adv. Phys. Org. Chem. 35, 193–318 (2000)
Silvi, M., Arceo, E., Jurberg, I. D., Cassani, C. & Melchiorre, P. Enantioselective organocatalytic alkylation of aldehydes and enals driven by the direct photoexcitation of enamines. J. Am. Chem. Soc. 137, 6120–6123 (2015)
Bahamonde, A. & Melchiorre, P. Mechanism of the stereoselective α-alkylation of aldehydes driven by the photochemical activity of enamines. J. Am. Chem. Soc. 138, 8019–8030 (2016)
Studer, A. & Curran, D. P. Catalysis of radical reactions: a radical chemistry perspective. Angew. Chem. Int. Ed. 55, 58–102 (2016)
Cecere, G., König, C. M., Alleva, J. L. & MacMillan, D. W. C. Enantioselective direct α-amination of aldehydes via a photoredox mechanism: a strategy for asymmetric amine fragment coupling. J. Am. Chem. Soc. 135, 11521–11524 (2013)
Filippini, G., Silvi, M. & Melchiorre, P. Enantioselective formal α-methylation and α-benzylation of aldehydes by means of photo-organocatalysis. Angew. Chem. Int. Ed. 56, 4447–4451 (2017)
Arceo, E., Bahamonde, A., Bergonzini, G. & Melchiorre, P. Enantioselective direct α-alkylation of cyclic ketones by means of photo-organocatalysis. Chem. Sci. 5, 2438–2442 (2014)
Shirakawa, S. & Maruoka, K. Recent developments in asymmetric phase-transfer reactions. Angew. Chem. Int. Ed. 52, 4312–4348 (2013)
Woz´niak, Ł., Murphy, J. J. & Melchiorre, P. Photo-organocatalytic enantioselective perfluoroalkylation of β-ketoesters. J. Am. Chem. Soc. 137, 5678–5681 (2015)
Silvi, M., Verrier, C., Rey, Y. P., Buzzetti, L. & Melchiorre, P. Visible-light excitation of iminium ions enables the enantioselective catalytic β-alkylation of enals. Nat. Chem. 9, 868–873 (2017)
Mariano, P. S. Electron-transfer mechanisms in photochemical transformations of iminium salts. Acc. Chem. Res. 16, 130–137 (1983)
Taylor, M. S. & Jacobsen, E. N. Asymmetric catalysis by chiral hydrogen-bond donors. Angew. Chem. Int. Ed. 45, 1520–1543 (2006)
Bach, T., Bergmann, H., Grosch, B. & Harms, K. Highly enantioselective intra- and intermolecular [2 + 2] photocycloaddition reactions of 2-quinolones mediated by a chiral lactam host:host–guest interactions, product configuration, and the origin of the stereoselectivity in solution. J. Am. Chem. Soc. 124, 7982–7990 (2002)
Bauer, A., Westkämper, F., Grimme, S. & Bach, T. Catalytic enantioselective reactions driven by photoinduced electron transfer. Nature 436, 1139–1140 (2005). Seminal example of enantioselective organocatalysis of photochemical reactions in the excited state
Alonso, R. & Bach, T. A chiral thioxanthone as an organocatalyst for enantioselective [2 + 2] photocycloaddition reactions induced by visible light. Angew. Chem. Int. Ed. 53, 4368–4371 (2014)
Brimioulle, R. & Bach, T. Enantioselective Lewis acid catalysis of intramolecular enone [2 + 2] photocycloaddition reactions. Science 342, 840–843 (2013)
Vallavoju, N., Selvakumar, S., Jockusch, S., Sibi, M. P. & Sivaguru, J. Enantioselective organo-photocatalysis mediated by atropisomeric thiourea derivatives. Angew. Chem. Int. Ed. 53, 5604–5608 (2014)
Madarász, Á. et al. Thiourea derivatives as Brønsted acid organocatalysts. ACS Catal. 6, 4379–4387 (2016)
Emmanuel, M. A., Greenberg, N. R., Oblinsky, D. G. & Hyster, T. K. Accessing non-natural reactivity by irradiating nicotinamide-dependent enzymes with light. Nature 540, 414–417 (2016). Landmark demonstration that light excitation of cofactors can alter the natural reactivity of enzymes
Huisman, G. W., Liang, J. & Krebber, A. Practical chiral alcohol manufacture using ketoreductases. Curr. Opin. Chem. Biol. 14, 122–129 (2010)
Fukuzumi, S., Hironaka, K. & Tanaka, T. Photoreduction of alkyl halides by an NADH model compound. An electron transfer chain mechanism. J. Am. Chem. Soc. 105, 4722–4727 (1983)
Bornscheuer, U. T. et al. Engineering the third wave of biocatalysis. Nature 485, 185–194 (2012)
Huo, H. et al. Asymmetric photoredox transition-metal catalysis activated by visible light. Nature 515, 100–103 (2014)
Cambié, D., Bottecchia, C., Straathof, N. J. W., Hessel, V. & Noël, T. Applications of continuous-flow photochemistry in organic synthesis, material science, and water treatment. Chem. Rev. 116, 10276–10341 (2016)
Mukherjee, S., Yang, J. W., Hoffmann, S. & List, B. Asymmetric enamine catalysis. Chem. Rev. 107, 5471–5569 (2007)
Lelais, G. & MacMillan, D. W. C. Modern strategies in organic catalysis: the advent and development of iminium activation. Aldrichimica Acta 39, 79–87 (2006)
Enders, D., Niemeier, O. & Henseler, A. Organocatalysis by N-heterocyclic carbenes. Chem. Rev. 107, 5606–5655 (2007)
Breslow, R. On the mechanism of thiamine action. IV. Evidence from studies on model systems. J. Am. Chem. Soc. 80, 3719–3726 (1958)
Sheehan, J. & Hara, T. Asymmetric thiazolium salt catalysis of the benzoin condensation. J. Org. Chem. 39, 1196–1199 (1974)
Enders, D. & Kallfass, U. An efficient nucleophilic carbene catalyst for the asymmetric benzoin condensation. Angew. Chem. Int. Ed. 41, 1743–1745 (2002)
Knowles, R. R. & Jacobsen, E. N. Attractive noncovalent interactions in asymmetric catalysis: links between enzymes and small molecule catalysts. Proc. Natl Acad. Sci. USA 107, 20678–20685 (2010)
Sigman, M. & Jacobsen, E. N. Schiff base catalysts for the asymmetric Strecker reaction identified and optimized from parallel synthetic libraries. J. Am. Chem. Soc. 120, 4901–4902 (1998)
Reisman, S. E., Doyle, A. G. & Jacobsen, E. N. Enantioselective thiourea-catalyzed additions to oxocarbenium ions. J. Am. Chem. Soc. 130, 7198–7199 (2008)
Akiyama, T., Itoh, J., Yokota, K. & Fuchibe, K. Enantioselective Mannich-type reaction catalyzed by a chiral Brønsted acid. Angew. Chem. Int. Ed. 43, 1566–1568 (2004)
Uraguchi, D. & Terada, M. Chiral Brønsted acid-catalyzed direct Mannich reactions via electrophilic activation. J. Am. Chem. Soc. 126, 5356–5357 (2004)
Parmar, D., Sugiono, E., Raja, S. & Rueping, M. Complete field guide to asymmetric BINOL-phosphate derived Brønsted acid and metal catalysis: history and classification by mode of activation; Brønsted acidity, hydrogen bonding, ion pairing, and metal phosphates. Chem. Rev. 114, 9047–9153 (2014)
Brak, K. & Jacobsen, E. N. Asymmetric ion-pairing catalysis. Angew. Chem. Int. Ed. 52, 534–561 (2013)
Staveness, D., Bosque, I. & Stephenson, C. R. J. Free radical chemistry enabled by visible light-induced electron transfer. Acc. Chem. Res. 49, 2295–2306 (2016)
Acknowledgements
P.M. thanks the Generalitat de Catalunya (CERCA Program), Agencia Estatal de Investigación (AEI) (CTQ2016-75520-P), and the European Research Council (ERC 681840-CATA-LUX) for financial support. M.S. thanks the EU for a Horizon 2020 Marie Skłodowska-Curie Fellowship (grant 744242).
Author information
Authors and Affiliations
Contributions
P.M. outlined the content of the Review and defined its scope. M.S. and P.M. worked together to prepare and edit the manuscript, figures and references.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Additional information
Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Silvi, M., Melchiorre, P. Enhancing the potential of enantioselective organocatalysis with light. Nature 554, 41–49 (2018). https://doi.org/10.1038/nature25175
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nature25175
This article is cited by
-
Red light-driven electron sacrificial agents-free photoreduction of inert aryl halides via triplet-triplet annihilation
Nature Communications (2023)
-
Photochemical diversification of strong C(sp3)–H bonds enabled by allyl bromide and sodium fluoride
Nature Synthesis (2023)
-
A general arene C–H functionalization strategy via electron donor–acceptor complex photoactivation
Nature Chemistry (2023)
-
Light-empowered contra-thermodynamic stereochemical editing
Nature Reviews Chemistry (2022)
-
Enantioselective [2+2]-cycloadditions with triplet photoenzymes
Nature (2022)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.