Towards the targeted protein degradation of CK2: design and synthesis of CAM4066-based PROTACs

• Sophie Day-Riley,
• Sona Krajcovicova,
• Aryaman Raj Sokhal,
• Jan L. Venne,
• Paul Brear,
• Marko Hyvönen,
• Benjamin C. Whitehurst,
• Jason S. Carroll and
• David R. Spring

Beilstein J. Org. Chem. 2026, 22, 611–619, doi:10.3762/bjoc.22.47

• off-target effects and incomplete or transient CK2 suppression. PROTACs offer an alternative strategy by inducing proteasome-mediated degradation, with potential advantages in potency, selectivity, and duration of action. Herein, a series of CK2-targeting PROTACs has been designed and synthesised. By

• conjugating a CAM4066-derived warhead to CRBN or VHL ligands, four VHL-recruiting PROTACs, were prepared using PEG and alkyl linkers, alongside two CRBN-recruiting analogues featuring constrained linkers. A ligand–linker analogue in which a linker is projected from the solvent-exposed region of CK2α retained

• binding affinity comparable to CAM4066, confirming that linker installation is tolerated and preserves key interactions in the αD and ATP sites. Keywords: CAM4066; casein kinase 2 (CK2); PROTACs; targeted protein degradation; Introduction Protein kinases form a large family of more than 500 enzymes that

Design and synthesis of an erdafitinib-based selective FGFR2 degrader

• Yumeng Jin,
• Shidong Wang,
• Sihan Pan,
• Shuqi Huang,
• Weichen Zhou,
• Xiaohao Huang,
• Lei Zheng and
• Lingfeng Chen

Beilstein J. Org. Chem. 2026, 22, 583–591, doi:10.3762/bjoc.22.44

• degrader. LC-JD-6 as a selective degrader for FGFR2 Pharmacologically, the capacity of PROTACs to discriminate between intended and unintended targets represents a pivotal attribute that mitigates adverse off-target effects. Therefore, LC-JD-6 underwent in vitro profiling against diverse FGFR subtypes to

• reduction of over 80% in FGFR2 protein levels, with negligible effects on the other subtypes. These findings establish LC-JD-6 as a highly selective FGFR2 degrader. LC-JD-6 reduced the expression of membrane-bound FGFR2 Since most PROTACs reported to date act on intracellular targets, we examined whether LC

• . Synthesis of PROTACs towards FGFR2. Reagents and conditions: (a) K2CO3, Pd (dppf)Cl2, 1,4-dioxane/H2O 4:1, 100 °C, 5 h; (b) 3,5-dimethoxyaniline, Pd2(dba)3, BINAP, Cs2CO3, toluene, 100 °C, 12 h; (c) (2-bromoethoxy)-tert-butyldimethylsilane, NaH, DMF, rt, 12 h; (d) tetrabutylammonium fluoride, THF rt, 12 h

Synthesis of a HDAC inhibitor–nanogold probe for cryo-EM visualization in class I HDAC co-repressor complexes

• Wiktoria A. Pytel,
• John W. R. Schwabe and
• James T. Hodgkinson

Beilstein J. Org. Chem. 2026, 22, 480–485, doi:10.3762/bjoc.22.35

• functionalized this position with linkers for the development of HDAC1–3 proteolysis targeting chimeras (PROTACs) [14][18]. Alkyl-linker lengths of approximately 12 atoms and greater were the most effective degraders [18]. We chose the commercially available amine functionalized nanogold particles (Au–NH2

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• ; Introduction Targeted protein degradation (TPD) has transformed the field of drug discovery [1][2]. Utilizing proximity-induced pharmacological strategies [3], this method has fostered the creation of numerous molecular glues and proteolysis-targeting chimeras (PROTACs). By manipulation of the internal

• small molecule inhibitors into PROTACs. The RAS proteins, once seen as drug-resistant, became susceptible and a series of covalent inhibitors [5][6][7] were synthesized to bind to KRASG12C. The application of the PROTAC principle has demonstrated the feasibility of endogenous degradation of KRAS [8][9

• heterocyclic fragment into the glutarimide core, creating potential CRBN ligands and crucial building blocks for assembling PROTACs. In this paper, a more convenient diazo reagent 5 is introduced and its effectiveness in reacting with a broad variety of NH-heterocycles and in providing N-Boc-protected