Subscribe to RSS

DOI: 10.1055/a-2731-6203
Chemistry-Driven Integrated Innovation: Unleashing the Potential of PROTAC Technology
Authors
Funding We gratefully acknowledge financial support from the Postdoctoral Fellowship Program of CPSF (Grant No. GZC20231489), Natural Science Foundation of Shandong Province (Grant No. ZR2024QH201), China Postdoctoral Science Foundation (Grant No. 2023M742101), the Ministry of Science and Technology of the People's Republic of China (Grant No. 2023YFC2606500), Shandong Undergraduate Teaching Reform Research Project (Grant No. M2023290), Qilu Medical College Undergraduate Education Teaching Research Project (Grant No. qlyxjy-202309), and the Shandong Laboratory Program (Grant No. SYS202205). This work was supported in part by the Ministry of Science, Innovation and Universities of Spain through Grant PID2022-136725OB-I00/AEI/10.13039/501100011033/FEDER-UE awarded to L.M.-A. An institutional grant of the Fundación Ramón Areces (Madrid, Spain) to the CBMSO is also acknowledged. The CBMSO has been certified since 2023 as a Severo Ochoa Center of Excellence by AEI/MCI/10.13039/501100011033. L. M.-A. is a member of the Global Virus Network.
Abstract
Proteolysis-targeting chimeras (PROTACs) are driving medicinal chemistry progress, yet efficient synthesis and rational linker design remain two critical bottlenecks for their clinical translation. Those core challenges directly limit the advancement of PROTACs from preclinical research to practical application. This review focuses on state-of-the-art enabling chemical strategies to address these key bottlenecks, ensuring tight relevance to PROTACs development needs. The modular assembly can be streamlined by click chemistry, multicomponent, and late-stage C–H functionalizations, whereas microscale and solid-phase platforms can be used to deliver thousands of analogues in days without purification. In this work, we emphasize covalent sulfonyl fluoride warheads and photocaged or photoswitchable scaffolds that provide spatiotemporal control of degradation. The employment of dynamic combinatorial chemistry, DNA-encoded libraries, and intracellular self-assembly further expands chemical space and accelerates hit triage. At last, we outline how artificial intelligence-driven modeling integrates these data to predict linker length, exit vector geometry, and ADME profiles, shortening iterative design cycles. Collectively, these chemistry-centric innovations are turning PROTACs from a conceptual breakthrough into a practical drug-discovery engine by directly addressing the synthesis, optimization, and functional control challenges that have impeded their clinical advancement.
Publication History
Received: 24 January 2025
Accepted: 24 October 2025
Article published online:
15 December 2025
© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)
Georg Thieme Verlag KG
Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany
-
References
- 1 Békés M, Langley DR, Crews CM. PROTAC targeted protein degraders: the past is prologue. Nat Rev Drug Discov 2022; 21 (03) 181-200
- 2 Pettersson M, Crews CM. PROteolysis TArgeting Chimeras (PROTACs) - past, present and future. Drug Discov Today Technol 2019; 31: 15-27
- 3 Ruffilli C, Roth S, Rodrigo M, Boyd H, Zelcer N, Moreau K. Proteolysis targeting chimeras (PROTACs): a perspective on integral membrane protein degradation. ACS Pharmacol Transl Sci 2022; 5 (10) 849-858
- 4 Zhong G, Chang X, Xie W, Zhou X. Targeted protein degradation: advances in drug discovery and clinical practice. Signal Transduct Target Ther 2024; 9 (01) 308
- 5 Morvan J, Tang B, Ryabchuk P. et al. Enabling electrochemical, decarboxylative C(sp2 )-C(sp3 ) cross-coupling for parallel medicinal chemistry. Eur J Med Chem 2025; 291: 117583
- 6 Zhao C, Dekker FJ. Novel design strategies to enhance the efficiency of proteolysis targeting chimeras. ACS Pharmacol Transl Sci 2022; 5 (09) 710-723
- 7 Zhao L, Zhao J, Zhong K, Tong A, Jia D. Targeted protein degradation: mechanisms, strategies and application. Signal Transduct Target Ther 2022; 7 (01) 113
- 8 Zhou Y, Xu S, López-Carrobles N. et al. Recent advances in the molecular design and applications of proteolysis targeting chimera-based multi-specific antiviral modality. Acta Materia Med 2023; 2 (03) 285-298
- 9 Bhole RP, Kute PR, Chikhale RV, Bonde CG, Pant A, Gurav SS. Unlocking the potential of PROTACs: a comprehensive review of protein degradation strategies in disease therapy. Bioorg Chem 2023; 139: 106720
- 10 Gao H, Sun X, Rao Y. PROTAC technology: opportunities and challenges. ACS Med Chem Lett 2020; 11 (03) 237-240
- 11 Hughes SJ, Testa A, Thompson N, Churcher I. The rise and rise of protein degradation: opportunities and challenges ahead. Drug Discov Today 2021; 26 (12) 2889-2897
- 12 Poongavanam V, Atilaw Y, Siegel S. et al. Linker-dependent folding rationalizes PROTAC cell permeability. J Med Chem 2022; 65 (19) 13029-13040
- 13 Feng L, Wang KY, Lv XL, Yan TH, Li JR, Zhou HC. Modular total synthesis in reticular chemistry. J Am Chem Soc 2020; 142 (06) 3069-3076
- 14 Lehmann JW, Blair DJ, Burke MD. Towards the generalized iterative synthesis of small molecules. Nat Rev Chem 2018; 2 (02) 115
- 15 Li J, Ballmer SG, Gillis EP. et al. Synthesis of many different types of organic small molecules using one automated process. Science 2015; 347 (6227) 1221-1226
- 16 Blay V, Tolani B, Ho SP, Arkin MR. High-throughput screening: today's biochemical and cell-based approaches. Drug Discov Today 2020; 25 (10) 1807-1821
- 17 Dong Y, Ma T, Xu T. et al. Characteristic roadmap of linker governs the rational design of PROTACs. Acta Pharm Sin B 2024; 14 (10) 4266-4295
- 18 Zhang G, Zhang J, Gao Y, Li Y, Li Y. Strategies for targeting undruggable targets. Expert Opin Drug Discov 2022; 17 (01) 55-69
- 19 Mslati H, Gentile F, Pandey M, Ban F, Cherkasov A. PROTACable is an integrative computational pipeline of 3-D modeling and deep learning to automate the de novo design of PROTACs. J Chem Inf Model 2024; 64 (08) 3034-3046
- 20 Pineda-Castañeda HM, Rivera-Monroy ZJ, Maldonado M. Copper(I)-catalyzed alkyne–azide cycloaddition (CuAAC) “Click” reaction: a powerful tool for functionalizing polyhydroxylated platforms. ACS Omega 2023; 8 (04) 3650-3666
- 21 Yang C, Tripathi R, Wang B. Click chemistry in the development of PROTACs. RSC Chem Biol 2023; 5 (03) 189-197
- 22 Wurz RP, Dellamaggiore K, Dou H. et al. A “click chemistry platform” for the rapid synthesis of bispecific molecules for inducing protein degradation. J Med Chem 2018; 61 (02) 453-461
- 23 Cross JM, Coulson ME, Smalley JP. et al. A 'click' chemistry approach to novel entinostat (MS-275) based class I histone deacetylase proteolysis targeting chimeras. RSC Med Chem 2022; 13 (12) 1634-1639
- 24 Dong J, Ma F, Cai M. et al. Heat shock protein 90 interactome-mediated proteolysis targeting chimera (HIM-PROTAC) degrading glutathione peroxidase 4 to trigger ferroptosis. J Med Chem 2024; 67 (18) 16712-16736
- 25 Liu C, Chen Z, Chen T. et al. Re-evaluating PIN1 as a therapeutic target in oncology using neutral inhibitors and PROTACs. J Med Chem 2024; 67 (17) 15780-15795
- 26 Geng Z, Shin JJ, Xi Y, Hawker CJ. Click chemistry strategies for the accelerated synthesis of functional macromolecules. J Polym Sci 2021; 59 (11) 963-1042
- 27 Bhela IP, Ranza A, Balestrero FC. et al. A versatile and sustainable multicomponent platform for the synthesis of protein degraders: proof-of-concept application to BRD4-degrading PROTACs. J Med Chem 2022; 65 (22) 15282-15299
- 28 Zhu L, Hu S, Yan X. et al. Ugi reaction-assisted assembly of covalent PROTACs against glutathione peroxidase 4. Bioorg Chem 2023; 134: 106461
- 29 Arndt CM, Bitai J, Brunner J. et al. One-pot synthesis of cereblon proteolysis targeting chimeras via photoinduced C(sp(2))-C(sp(3)) cross coupling and amide formation for proteolysis targeting chimera library synthesis. J Med Chem 2023; 66 (24) 16939-16952
- 30 Guillemard L, Kaplaneris N, Ackermann L, Johansson MJ. Late-stage C-H functionalization offers new opportunities in drug discovery. Nat Rev Chem 2021; 5 (08) 522-545
- 31 Antermite D, Friis SD, Johansson JR, Putra OD, Ackermann L, Johansson MJ. Late-stage synthesis of heterobifunctional molecules for PROTAC applications via ruthenium-catalysed C‒H amidation. Nat Commun 2023; 14 (01) 8222
- 32 Stevens R, Bendito-Moll E, Battersby DJ. et al. Integrated direct-to-biology platform for the nanoscale synthesis and biological evaluation of PROTACs. J Med Chem 2023; 66 (22) 15437-15452
- 33 Plesniak MP, Taylor EK, Eisele F. et al. Rapid PROTAC discovery platform: nanomole-scale array synthesis and direct screening of reaction mixtures. ACS Med Chem Lett 2023; 14 (12) 1882-1890
- 34 Tian Y, Seifermann M, Bauer L. et al. High-throughput miniaturized synthesis of PROTAC-like molecules. Small 2024; 20 (26) e2307215
- 35 Guo L, Zhou Y, Nie X. et al. A platform for the rapid synthesis of proteolysis targeting chimeras (Rapid-TAC) under miniaturized conditions. Eur J Med Chem 2022; 236: 114317
- 36 Yan KN, Nie YQ, Wang JY. et al. Accelerating PROTACs discovery through a direct-to-biology platform enabled by modular photoclick chemistry. Adv Sci (Weinh) 2024; 11 (26) e2400594
- 37 Hartman AM, Elgaher WAM, Hertrich N, Andrei SA, Ottmann C, Hirsch AKH. Discovery of small-molecule stabilizers of 14-3-3 protein–protein interactions via dynamic combinatorial chemistry. ACS Med Chem Lett 2020; 11 (05) 1041-1046
- 38 Jana S, Panda D, Saha P, Pantoş GD, Dash J. Dynamic generation of G-quadruplex DNA ligands by target-guided combinatorial chemistry on a magnetic nanoplatform. J Med Chem 2019; 62 (02) 762-773
- 39 Diehl CJ, Salerno A, Ciulli A. Ternary complex-templated dynamic combinatorial chemistry for the selection and identification of homo-PROTACs. Angew Chem Int Ed Engl 2024; 63 (25) e202319456
- 40 Lebraud H, Wright DJ, Johnson CN, Heightman TD. Protein degradation by in-cell self-assembly of proteolysis targeting chimeras. ACS Cent Sci 2016; 2 (12) 927-934
- 41 Gui W, Giardina SF, Balzarini M, Barany F, Kodadek T. Reversible assembly of proteolysis targeting chimeras. ACS Chem Biol 2023; 18 (07) 1582-1593
- 42 Giardina SF, Valdambrini E, Singh PK. et al. Combinatorial ubiquitination rEal-time PROteolysis (CURE-PROs): a modular platform for generating reversible, self-assembling bifunctional targeted degraders. J Med Chem 2024; 67 (07) 5473-5501
- 43 Chang M, Gao F, Pontigon D, Gnawali G, Xu H, Wang W. Bioorthogonal PROTAC prodrugs enabled by on-target activation. J Am Chem Soc 2023; 145 (25) 14155-14163
- 44 Do TC, Lau JW, Sun C. et al. Hypoxia deactivates epigenetic feedbacks via enzyme-derived clicking proteolysis-targeting chimeras. Sci Adv 2022; 8 (50) eabq2216
- 45 Liu J, Chen H, Kaniskan HU. et al. TF-PROTACs enable targeted degradation of transcription factors. J Am Chem Soc 2021; 143 (23) 8902-8910
- 46 Chen Q, Liu C, Wang W. et al. Optimization of PROTAC ternary complex using DNA encoded library approach. ACS Chem Biol 2023; 18 (01) 25-33
- 47 Mason JW, Chow YT, Hudson L. et al. DNA-encoded library-enabled discovery of proximity-inducing small molecules. Nat Chem Biol 2024; 20 (02) 170-179
- 48 Sinatra L, Yang J, Schliehe-Diecks J. et al. Solid-phase synthesis of cereblon-recruiting selective histone deacetylase 6 degraders (HDAC6 PROTACs) with antileukemic activity. J Med Chem 2022; 65 (24) 16860-16878
- 49 Shah RR, De Vita E, Sathyamurthi PS. et al. Structure-guided design and optimization of covalent VHL-targeted sulfonyl fluoride PROTACs. J Med Chem 2024; 67 (06) 4641-4654
- 50 Carvalho LAR, Sousa BB, Zaidman D, Kiely-Collins H, Bernardes GJL. Design and evaluation of PROTACs targeting acyl protein thioesterase 1. ChemBioChem 2024; 25 (04) e202300736
- 51 Kounde CS, Tate EW. Photoactive bifunctional degraders: precision tools to regulate protein stability. J Med Chem 2020; 63 (24) 15483-15493
- 52 Li Z, Ma S, Yang X. et al. Development of photocontrolled BRD4 PROTACs for tongue squamous cell carcinoma (TSCC). Eur J Med Chem 2021; 222: 113608
- 53 Zhu Y, Xu P, Huang X. et al. From rate-limiting enzyme to therapeutic target: The promise of NAMPT in neurodegenerative diseases. Front Pharmacol 2022; 13: 920113
- 54 Cheng J, Zhang J, He S, Li M, Dong G, Sheng C. Photoswitchable PROTACs for reversible and spatiotemporal regulation of NAMPT and NAD. Angew Chem Int Ed Engl 2024; 63 (12) e202315997
- 55 Jin YH, Lu MC, Wang Y. et al. Azo-PROTAC: novel light-controlled small-molecule tool for protein knockdown. J Med Chem 2020; 63 (09) 4644-4654
- 56 Naro Y, Darrah K, Deiters A. Optical control of small molecule-induced protein degradation. J Am Chem Soc 2020; 142 (05) 2193-2197
- 57 Jia G, Jiang Y, Li X. Targeted drug conjugates in cancer therapy: challenges and opportunities. Pharmaceutical Science Advances 2024; 2 (2024) 100048
- 58 Imaide S, Riching KM, Makukhin N. et al. Trivalent PROTACs enhance protein degradation via combined avidity and cooperativity. Nat Chem Biol 2021; 17 (11) 1157-1167
- 59 Lv D, Pal P, Liu X. et al. Development of a BCL-xL and BCL-2 dual degrader with improved anti-leukemic activity. Nat Commun 2021; 12 (01) 6896
- 60 Zheng M, Huo J, Gu X. et al. Rational design and synthesis of novel dual PROTACs for simultaneous degradation of EGFR and PARP. J Med Chem 2021; 64 (11) 7839-7852
- 61 Wang S, Feng Z, Qu C. et al. Novel amphiphilic PROTAC with enhanced pharmacokinetic properties for ALK protein degradation. J Med Chem 2024; 67 (12) 9842-9856
- 62 Chen M, Zhou P, Kong Y. et al. Inducible degradation of oncogenic nucleolin using an aptamer-based PROTAC. J Med Chem 2023; 66 (02) 1339-1348
- 63 Dragovich PS, Pillow TH, Blake RA. et al. Antibody-mediated delivery of chimeric BRD4 degraders. Part 1: Exploration of antibody linker, payload loading, and payload molecular properties. J Med Chem 2021; 64 (05) 2534-2575
- 64 Dragovich PS, Pillow TH, Blake RA. et al. Antibody-mediated delivery of chimeric BRD4 degraders. Part 2: improvement of in vitro antiproliferation activity and in vivo antitumor efficacy. J Med Chem 2021; 64 (05) 2576-2607
- 65 Du S, Hu X, Lindsley CW, Zhan P. Medicinal chemistry education: Emphasize fundamentals and skillfully integrate knowledge. J Med Chem 2024; 67 (22) 19929-19931
