Sulfoximines: A Neglected Opportunity in Medicinal Chemistry

Copper-catalyzed oxidative decarboxylative coupling of α-keto acids and sulfoximines

The formation of N-aroylsulfoximines via a copper-catalyzed oxidative decarboxylative coupling of α-keto acids with NH-sulfoximines is reported.

Rhodium-catalyzed benzoisothiazole synthesis by tandem annulation reactions of sulfoximines and activated olefins

Rhodium(iii)-catalyzed N-directed ortho C–H activation reactions have been developed for the synthesis of unique heterocyclic benzoisothiazoles.

A divergent and metal free synthesis of sulfoximine tethered imidazoles, imidazopyridines, imidazothiazoles, imidazobenzothiazines, thiazoles and selenazoles

A divergent and metal free approach has been successfully developed for the synthesis of sulfoximine tethered heterocycles from a α-bromoalkanone building block.

Synthesis of NH-sulfoximines from sulfides by chemoselective one-pot N- and O-transfers

Direct synthesis of NH-sulfoximines from sulfides has been achieved through O and NH transfer in the same reaction, occurring with complete selectivity.

Access to N-cyanosulfoximines by transition metal-free iminations of sulfoxides

Sulfoxides are stereospecifically converted to N-cyanosulfoximines using N-chlorosuccinimide (NCS) as oxidising agent and cyanamide as nucleophilic amine source.

Direct N-acylation of sulfoximines with carboxylic acids catalyzed by the B3NO2 heterocycle

Dehydrative coupling of sulfoximines and carboxylic acids is rendered catalytic by a heterocyclic catalyst featuring the B₃NO₂ ring system.

Synthesis of a Sulfonimidamide-Based Analog of Tasisulam and Its Biological Evaluation in the Melanoma Cell Lines SKMel23 and A375

Tasisulam is a promising antitumor agent with complex pharmacology, which is used as an antiproliferative agent in patients with metastatic melanoma and other solid tumors. Phase 2 melanoma studies showed promising results but had to be stopped because of insufficient tasisulam clearance leading to toxic side effects. To reduce the negative effects of tasisulam, we synthesized a novel sulfonimidamide-based analog to evaluate its antiproliferative effects in comparison to the original compound by performing a cell proliferation assay in melanoma cell lines SKMel23 and A375. The results revealed that the analog had inhibitory effects on the proliferation comparable to tasisulam in both investigated cell lines. These results could contribute to a reduced toxicity of tasisulam and lead to further clinical trials in metastatic melanoma.

Copper-catalyzed N-methylation/ethylation of sulfoximines

A protocol for the copper-catalyzed N-methylation of sulfoximines with di-tert-butyl peroxide (DTBP) was developed. This protocol has good functional group tolerance leading to N-methylated sulfoximines in moderate to good yields. Besides, N-ethylation of sulfoximines was achieved in the presence of bis(1,1-dimethylpropyl)peroxide as the ethylating agent under a standard procedure.

Metal-Free, Phosphonium Salt-Mediated Sulfoximination of Azine N-Oxides: Approach for the Synthesis of N-Azine Sulfoximines

Herein, we report a simple and metal-free method for the synthesis of N-azine sulfoximines by the nucleophilic substitution of azine N-oxides with NH-sulfoximines. The present method works at room temperature with wide functional group compatibility and gives several unprecedented N-azine sulfoximines. The reaction conditions were also found suitable with enantiopure substrates and furnished products without any racemization. It also finds an application in the sulfoximination of azine-based functional molecules such as 2,2'-bipyridine, 1,10-phenanthroline, and quinine.

Conformational Adaption May Explain the Slow Dissociation Kinetics of Roniciclib (BAY 1000394), a Type I CDK Inhibitor with Kinetic Selectivity for CDK2 and CDK9

Roniciclib (BAY 1000394) is a type I pan-CDK (cyclin-dependent kinase) inhibitor which has revealed potent efficacy in xenograft cancer models. Here, we show that roniciclib displays prolonged residence times on CDK2 and CDK9, whereas residence times on other CDKs are transient, thus giving rise to a kinetic selectivity of roniciclib. Surprisingly, variation of the substituent at the 5-position of the pyrimidine scaffold results in changes of up to 3 orders of magnitude of the drug-target residence time. CDK2 X-ray cocrystal structures have revealed a DFG-loop adaption for the 5-(trifluoromethyl) substituent, while for hydrogen and bromo substituents the DFG loop remains in its characteristic type I inhibitor position. In tumor cells, the prolonged residence times of roniciclib on CDK2 and CDK9 are reflected in a sustained inhibitory effect on retinoblastoma protein (RB) phosphorylation, indicating that the target residence time on CDK2 may contribute to sustained target engagement and antitumor efficacy.

Transfer of Electrophilic NH Using Convenient Sources of Ammonia: Direct Synthesis of NH Sulfoximines from Sulfoxides

A new system for NH transfer is developed for the preparation of sulfoximines, which are emerging as valuable motifs for drug discovery. The protocol employs readily available sources of nitrogen without the requirement for either preactivation or for metal catalysts. Mixing ammonium salts with diacetoxyiodobenzene directly converts sulfoxides into sulfoximines. This report describes the first example of using of ammonia sources with diacetoxyiodobenzene to generate an electrophilic nitrogen center. Control and mechanistic studies suggest a short-lived electrophilic intermediate, which is likely to be PhINH or PhIN(+) .

Drugging ATR: progress in the development of specific inhibitors for the treatment of cancer

In this article, we review the ATR inhibitor field from initial pharmacological tools to first-generation clinical candidates with the potential to bring benefit to cancer patients. ATR is a critical part of the cell DNA-damage response. Over the past decade or more, compounds with weak ATR potency and low specificity have been used as tools in early studies to elucidate ATR pharmacology. More recently highly potent, selective and in vivo active ATR inhibitors have been developed enabling detailed preclinical in vitro and in vivo target assessment to be made. The published studies reveal the potential of ATR inhibitors for use as monotherapy or in combination with DNA-damaging agents. To date, VX-970 and AZD6738, have entered clinical assessment.

Sulfoximinocarbonylation of aryl halides using heterogeneous Pd/C catalyst

A heterogeneous Pd/C catalyzed three component protocol is developed for the sulfoximinocarbonylation of aryl halides.

Palladium nanoparticles catalyzed aroylation of NH-sulfoximines with aryl iodides

A novel approach towards aroylation of NH-sulfoximines with aryl iodides in the presence of carbon monoxide using Pd nanoparticles stabilized by a binaphthyl backbone (Pd-BNP) has been developed.

Stereoselective synthesis of 4-aminobenzo[c][1,2]thiazine via modification of the Harmata benzothiazine synthesis

A stereoselective synthesis of 4-aminobenzothiazines was developed through a modified Harmata benzothiazine synthesis.

Freezing the Bioactive Conformation to Boost Potency: The Identification of BAY 85-8501, a Selective and Potent Inhibitor of Human Neutrophil Elastase for Pulmonary Diseases

Human neutrophil elastase (HNE) is a key protease for matrix degradation. High HNE activity is observed in inflammatory diseases. Accordingly, HNE is a potential target for the treatment of pulmonary diseases such as chronic obstructive pulmonary disease (COPD), acute lung injury (ALI), acute respiratory distress syndrome (ARDS), bronchiectasis (BE), and pulmonary hypertension (PH). HNE inhibitors should reestablish the protease-anti-protease balance. By means of medicinal chemistry a novel dihydropyrimidinone lead-structure class was identified. Further chemical optimization yielded orally active compounds with favorable pharmacokinetics such as the chemical probe BAY-678. While maintaining outstanding target selectivity, picomolar potency was achieved by locking the bioactive conformation of these inhibitors with a strategically positioned methyl sulfone substituent. An induced-fit binding mode allowed tight interactions with the S2 and S1 pockets of HNE. BAY 85-8501 ((4S)-4-[4-cyano-2-(methylsulfonyl)phenyl]-3,6-dimethyl-2-oxo-1-[3-(trifluoromethyl)phenyl]-1,2,3,4-tetrahydropyrimidine-5-carbonitrile) was shown to be efficacious in a rodent animal model related to ALI. BAY 85-8501 is currently being tested in clinical studies for the treatment of pulmonary diseases.

N-Trifluoromethylthiolated Sulfoximines

Air- and moisture-stable N-trifluoromethylthio sulfoximines have been prepared from N-H-sulfoximines via the corresponding N-Br derivatives in excellent yields. The two-step process starts with an easy-to-perform bromination at the sulfoximine nitrogen, followed by a reaction with silver trifluoromethanethiolate. A one-pot reaction sequence allows difficult to prepare products to be obtained.