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二碘化钐催化有机反应的研究进展
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Abstract:
二碘化钐(SmI2)作为一种独特的单电子转移(SET)还原剂，自1977年被Kagan课题组首次系统报道以来，已成为有机合成中构建复杂分子骨架的核心工具。传统SmI2反应依赖化学计量比试剂，存在原子经济性低、废弃物排放多等局限。近年来，催化量SmI2体系的开发突破了Sm3+产物络合物难以解离的关键瓶颈，通过还原剂再生、电子循环、光化学驱动等策略实现了催化剂的高效循环。本文系统综述了SmI2催化反应的核心机制：使用化学计量比的牺牲金属还原剂、通过反向电子转移(BET)将电子循环回收钐，以及光化学再生的最新进展。
Samarium diiodide (SmI2), as a unique single-electron transfer (SET) reductant, has become a central tool in constructing complex molecular frameworks in organic synthesis since it was first systematically reported by Kagan’s group in 1977. Traditional SmI2 reactions rely on stoichiometric amounts of reagents, which have limitations such as low atom economy and high waste generation. In recent years, the development of catalytic SmI2 systems has overcome the key bottleneck of difficult dissociation of Sm3+-product complexes, achieving efficient catalyst turnover through reductant regeneration, electron cycling, as well as electrochemical and photochemical driving strategies. This review systematically summarizes the core mechanisms of SmI2-catalyzed reactions: the use of stoichiometric sacrificial metal reductants, electron cycling back to Sm through back electron transfer (BET), and the latest advances in photochemical regeneration.
| [1] | Girard, P., Namy, J.L. and Kagan, H.B. (1980) Divalent Lanthanide Derivatives in Organic Synthesis. 1. Mild Preparation of Samarium Iodide and Ytterbium Iodide and Their Use as Reducing or Coupling Agents. Journal of the American Chemical Society, 102, 2693-2698. https://doi.org/10.1021/ja00528a029 |
| [2] | Namy, J.L., Girard, P., Kagan, H.B. (1977) Divalent Lanthanide Derivatives in Organic Synthesis. I. Mild Preparation of Samarium Diiodide and Ytterbium Diiodide and Their Use as Reducing or Coupling Agents. Nouveau Journal de Chimie, 1, 5-7. |
| [3] | Nicolaou, K.C., Ellery, S.P. and Chen, J.S. (2009) Samarium Diiodide Mediated Reactions in Total Synthesis. Angewandte Chemie International Edition, 48, 7140-7165. https://doi.org/10.1002/anie.200902151 |
| [4] | Gao, Y. and Ma, D. (2022) Samarium Iodide-Mediated C-C Bond Formation in the Total Synthesis of Natural Products. Nature Synthesis, 1, 275-288. https://doi.org/10.1038/s44160-022-00046-z |
| [5] | Conticello, V.P., Gin, D.L. and Grubbs, R.H. (1992) Ring-Opening Metathesis Polymerization of Substituted Bicyclo[2.2.2]Octadienes: A New Precursor Route to Poly(1,4-Phenylenevinylene). Journal of the American Chemical Society, 114, 9708-9710. https://doi.org/10.1021/ja00050a088 |
| [6] | Ashida, Y., Arashiba, K., Nakajima, K. and Nishibayashi, Y. (2019) Molybdenum-Catalysed Ammonia Production with Samarium Diiodide and Alcohols or Water. Nature, 568, 536-540. https://doi.org/10.1038/s41586-019-1134-2 |
| [7] | Szostak, M., Fazakerley, N.J., Parmar, D. and Procter, D.J. (2014) Cross-Coupling Reactions Using Samarium(II) Iodide. Chemical Reviews, 114, 5959-6039. https://doi.org/10.1021/cr400685r |
| [8] | Procter, D.J., Flowers, R.A. and Skrydstrup, T. (2009) Organic Synthesis Using Samarium Diiodide: A Practical Guide. The Royal Society of Chemistry. |
| [9] | Corey, E.J. and Zheng, G.Z. (1997) Catalytic Reactions of Samarium (II) Iodide. Tetrahedron Letters, 38, 2045-2048. https://doi.org/10.1016/s0040-4039(97)00263-3 |
| [10] | Hélion, F. and Namy, J. (1999) Mischmetall: An Efficient and Low Cost Coreductant for Catalytic Reactions of Samarium Diiodide. The Journal of Organic Chemistry, 64, 2944-2946. https://doi.org/10.1021/jo9820667 |
| [11] | Aspinall, H.C., Greeves, N. and Valla, C. (2005) Samarium Diiodide-Catalyzed Diastereoselective Pinacol Couplings. Organic Letters, 7, 1919-1922. https://doi.org/10.1021/ol050256f |
| [12] | Ueda, T., Kanomata, N. and Machida, H. (2005) Synthesis of Planar-Chiral Paracyclophanes via Samarium(II)-Catalyzed Intramolecular Pinacol Coupling. Organic Letters, 7, 2365-2368. https://doi.org/10.1021/ol0506258 |
| [13] | Maity, S. and Flowers, R.A. (2019) Synthesis of Planar-Chiral Paracyclophanes via Samarium(II)-Catalyzed Intramolecular Pinacol Coupling. Journal of the American Chemical Society, 141, 3207-3216. https://doi.org/10.1021/jacs.8b13119 |
| [14] | Boyd, E.A., Shin, C., Charboneau, D.J., Peters, J.C. and Reisman, S.E. (2024) Reductive Samarium (Electro)Catalysis Enabled by SmIII-Alkoxide Protonolysis. Science, 385, 847-853. https://doi.org/10.1126/science.adp5777 |
| [15] | Huang, H., Garduño-Castro, M.H., Morrill, C. and Procter, D.J. (2019) Catalytic Cascade Reactions by Radical Relay. Chemical Society Reviews, 48, 4626-4638. https://doi.org/10.1039/c8cs00947c |
| [16] | Huang, H., McDouall, J.J.W. and Procter, D.J. (2019) SmI2-Catalysed Cyclization Cascades by Radical Relay. Nature Catalysis, 2, 211-218. https://doi.org/10.1038/s41929-018-0219-x |
| [17] | Agasti, S., Beattie, N.A., McDouall, J.J.W. and Procter, D.J. (2021) SmI2-Catalyzed Intermolecular Coupling of Cyclopropyl Ketones and Alkynes: A Link between Ketone Conformation and Reactivity. Journal of the American Chemical Society, 143, 3655-3661. https://doi.org/10.1021/jacs.1c01356 |
| [18] | Mansell, J.I., Yu, S., Li, M., Pye, E., Yin, C., Beltran, F., et al. (2024) Alkyl Cyclopropyl Ketones in Catalytic Formal [3 + 2] Cycloadditions: The Role of SmI2 Catalyst Stabilization. Journal of the American Chemical Society, 146, 12799-12807. https://doi.org/10.1021/jacs.4c03073 |
| [19] | Mini, A., Vyas, H., Gangani, A.J., Melada, M., Shin, A. and Sharma, A. (2025) Merging Ketyl Radical Chemistry and Allylboration via Strain Release: One-Pot Multicomponent Access to Sterically Congested Ketone-Functionalized Organoborons. Organic Letters, 27, 2902-2907. https://doi.org/10.1021/acs.orglett.5c00469 |
| [20] | Novaes, L.F.T., Liu, J., Shen, Y., Lu, L., Meinhardt, J.M. and Lin, S. (2021) Electrocatalysis as an Enabling Technology for Organic Synthesis. Chemical Society Reviews, 50, 7941-8002. https://doi.org/10.1039/d1cs00223f |
| [21] | Agasti, S., Beltran, F., Pye, E., Kaltsoyannis, N., Crisenza, G.E.M. and Procter, D.J. (2023) A Catalytic Alkene Insertion Approach to Bicyclo[2.1.1]Hexane Bioisosteres. Nature Chemistry, 15, 535-541. https://doi.org/10.1038/s41557-023-01135-y |
| [22] | Roy, D., Mansell, J.I., Barison, G., Yu, S., Katavic, R., Romano, C., et al. (2025) SmI2‐Catalyzed Coupling of Alkyl Housane Ketones and Alkenes in an Approach to Norbornanes. Angewandte Chemie International Edition, 64, e202512018. https://doi.org/10.1002/anie.202512018 |
| [23] | Walczak, M.A.A., Krainz, T. and Wipf, P. (2015) Ring-Strain-Enabled Reaction Discovery: New Heterocycles from Bicyclo[1.1.0]Butanes. Accounts of Chemical Research, 48, 1149-1158. https://doi.org/10.1021/ar500437h |
| [24] | Subbaiah, M.A.M. and Meanwell, N.A. (2021) Bioisosteres of the Phenyl Ring: Recent Strategic Applications in Lead Optimization and Drug Design. Journal of Medicinal Chemistry, 64, 14046-14128. https://doi.org/10.1021/acs.jmedchem.1c01215 |
| [25] | Chen, R., Bai, Y. and Wei, B. (2025) Samarium Redox Catalysis. Chemical Synthesis, 5, 62. https://doi.org/10.20517/cs.2025.22 |
| [26] | Parker, D., Dickins, R.S., Puschmann, H., Crossland, C. and Howard, J.A.K. (2002) Being Excited by Lanthanide Coordination Complexes: Aqua Species, Chirality, Excited-State Chemistry, and Exchange Dynamics. Chemical Reviews, 102, 1977-2010. https://doi.org/10.1021/cr010452+ |
| [27] | Tomar, M., Bhimpuria, R., Kocsi, D., Thapper, A. and Borbas, K.E. (2023) Photocatalytic Generation of Divalent Lanthanide Reducing Agents. Journal of the American Chemical Society, 145, 22555-22562. https://doi.org/10.1021/jacs.3c07508 |
| [28] | Bhimpuria, R., Charaf, R., Ye, K., Thapper, A., Sathyan, H., Ahlquist, M., et al. (2025) A Sm(II)-Based Catalyst for the Reduction of Dinitrogen, Nitrite, and Nitrate to Ammonia or Urea. Chem, 11, Article 102547. https://doi.org/10.1016/j.chempr.2025.102547 |
| [29] | Kuribara, T., Kaneki, A., Matsuda, Y. and Nemoto, T. (2024) Visible-Light-Antenna Ligand-Enabled Samarium-Catalyzed Reductive Transformations. Journal of the American Chemical Society, 146, 20904-20912. https://doi.org/10.1021/jacs.4c05414 |
| [30] | Tomar, M., Bosch, C., Everaert, J., Bhimpuria, R., Thapper, A., Orthaber, A., et al. (2024) Photocatalyst for Visible-Light-Driven Sm(II)-Mediated Reductions. Organic Letters, 26, 10752-10756. https://doi.org/10.1021/acs.orglett.4c03723 |
| [31] | Johansen, C.M., Boyd, E.A., Tarnopol, D.E. and Peters, J.C. (2024) Photodriven Sm(III)-To-Sm(II) Reduction for Catalytic Applications. Journal of the American Chemical Society, 146, 25456-25461. https://doi.org/10.1021/jacs.4c10053 |
