Eaton’s reagent-mediated metal-free and efficient synthesis of NH-sulfoximines

Computer-Aided Retrosynthesis for Greener and Optimal Total Synthesis of a Helicase-Primase Inhibitor Active Pharmaceutical Ingredient

This study leverages and upgrades the capabilities of computer-aided retrosynthesis (CAR) in the systematic development of greener and more efficient total synthetic routes for the active pharmaceutical ingredient (API) IM-204, a helicase-primase inhibitor that demonstrated enhanced efficacy against Herpes simplex virus (HSV) infections. Using various CAR tools, several total synthetic routes were uncovered, evaluated, and experimentally validated, with the goal to maximize selectivity and yield and minimize the environmental impact. The CAR tools revealed several synthetic options under different constraints, which can overperform the patented synthetic route used as a reference. The selected CAR-based route demonstrated a significant improvement of the total yield from 8% (patented route) to 26%, along with a moderate improvement in the overall green performance. It was also shown that a human-in-the-loop approach can be synergistically combined with CAR to drive further improvements and deliver greener synthetic alternatives. This strategy further enhanced the green metrics by substituting solvents and merging two steps into one. These changes led to a significant improvement in the overall yield of IM-204 synthesis from 8 to 35%. Additionally, the green performance score, based on the GreenMotion metrics, was improved from 0 to 18, and the total cost of the building blocks was reduced by 550-fold. This work demonstrates the potential of CAR in drug development, highlighting its capacity to streamline synthesis processes, reduce environmental footprint, and lower production costs, thereby advancing the field toward more efficient and sustainable practices.

Improving Aqueous Solubility and In Vitro Pharmacokinetic Properties of the 3-Nitroimidazo[1,2-a]pyridine Antileishmanial Pharmacophore

An antileishmanial structure−activity relationship (SAR) study focused on positions 2 and 8 of the imidazo[1,2-a]pyridine ring was conducted through the synthesis of 22 new derivatives. After being screened on the promatigote and axenic amastigote stages of Leishmania donovani and L. infantum, the best compounds were tested against the intracellular amastigote stage of L. infantum and evaluated regarding their in vitro physicochemical and pharmacokinetic properties, leading to the discovery of a new antileishmanial6-chloro-3-nitro-8-(pyridin-4-yl)-2-[(3,3,3-trifluoropropylsulfonyl)methyl]imidazo[1,2-a]pyridine hit. It displayed low cytotoxicities on both HepG2 and THP1 cell lines (CC50 > 100 µM) associated with a good activity against the intracellular amastigote stage of L. infantum (EC50 = 3.7 µM versus 0.4 and 15.9 µM for miltefosine and fexinidazole, used as antileishmanial drug references). Moreover, in comparison with previously reported derivatives in the studied series, this compound displayed greatly improved aqueous solubility, good mouse microsomal stability (T1/2 > 40 min) and high gastrointestinal permeability in a PAMPA model, making it an ideal candidate for further in vivo studies on an infectious mouse model.

Synthesis and Transformations of NH-Sulfoximines

Recent years have seen a marked increase in the occurrence of sulfoximines in the chemical sciences, often presented as valuable motifs for medicinal chemistry. This has been prompted by both pioneering works taking sulfoximine containing compounds into clinical trials and the concurrent development of powerful synthetic methods. This review covers recent developments in the synthesis of sulfoximines concentrating on developments since 2015. This includes extensive developments in both S-N and S-C bond formations. Flow chemistry processes for sulfoximine synthesis are also covered. Finally, subsequent transformations of sulfoximines, particularly in N-functionalization are reviewed, including N-S, N-P, N-C bond forming processes and cyclization reactions.

Synthesis of Six-Membered N-Heterocycle Frameworks Based on Intramolecular Metal-Free N-Centered Radical Chemistry

The formation of intramolecular C-N bond represents a powerful strategy in organic transformation as the great importance of N-heterocycles in the fields of natural products and bioactive molecules. This personal account describes the synthesis of cyclic phosphinamidation, benzosultam, benzosulfoximine, phenanthridine and their halogenated compounds through transition-metal-free intramolecular oxidative C-N bond formation. Mechanism study reveals that N-X bond is initially formed under the effect of hypervalent halogen, which is very unstable and easily undergoes thermal or light homolytic cleavage to generate nitrogen radical. Then the nitrogen radical is trapped by the arene to give aryl radical. Rearomatization of aryl radical under the oxidant to provide corresponding N-heterocycle. Under suitable conditions, the N-heterocycles can be further transformed to halogenated N-heterocycles.

Synthesis of NH-Sulfoximines by Using Recyclable Hypervalent Iodine(III) Reagents under Aqueous Micellar Conditions

The synthesis of NH-sulfoximines from sulfides has been first developed under mild conditions in an aqueous solution with surfactant TPGS-750-M as the catalyst at room temperature. In this newly developed process, a simple and convenient recycling strategy to regenerate the indispensable hypervalent iodine(III) is used. The resulting 1,2,3-trifluoro-5-iodobezene can be recovered almost quantitively from the mixture by liquid-liquid extraction and then oxidized to give the corresponding iodine(III) species. This optimized procedure is compatible with a broad range of functional groups and can be easily performed on a gram scale, providing a green protocol for the synthesis of sulfoximines.

N-(2,3,5,6-Tetrafluoropyridyl)sulfoximines: synthesis, X-ray crystallography, and halogen bonding

N-(Tetrafluoropyridyl)sulfoximines are obtained from NH-sulfoximines and pentafluoropyridine under solution-based or mechanochemical conditions, and the solid-state structures of 26 products have been determined by X-ray diffraction analysis.