One-Pot Synthesis of N-Iodo Sulfoximines from Sulfides

PIDA/I2-mediated photo-induced aerobic N-acylation of sulfoximines with methylarenes

A visible-light-promoted, PIDA/I2-mediated acylation of NH-sulfoximines with methylarenes as an acyl source has been achieved. This transition metal and photosensitizer-free approach provides easy access to N-acylsulfoximines via oxidative coupling of sulfoximines with easily available methylarenes without using any peroxide source. Mechanistic investigations suggest the intermediacy of radicals and the importance of molecular oxygen.

Oxidation of N-trifluoromethylthio sulfoximines using NaOCl·5H2O

N-Trifluoromethylthio sulfoximines are biologically interesting compounds, but their potential is still poorly understood. The oxidation of N-trifluoromethylthio sulfoximines led to their corresponding sulfoxide derivatives as a new class of compounds, when using sodium hypochlorite pentahydrate (NaOCl·5H2O) as a green and relatively unexplored reagent. The reactions took place with a small excess of oxidant under environmentally friendly conditions in EtOAc for 16 h at room temperature. Noteworthy distinctions of this transformation are the simplicity, high selectivity, energy and cost efficiency, minimal amounts of non-hazardous waste, isolation of most of the products without the additional need for chromatographic purification, and simple scalability to gram reactions without deterioration of the yield. The reaction exhibited excellent green chemistry metrics with high atom economy (82.0%), actual atom economy (79.5%), reaction mass efficiency (79.7%), E-factor (16.48) and a very high EcoScale score (84.5). Competitive experiments demonstrated that electron-rich substrates are more reactive than their electron-poor counterparts. Furthermore, the Suzuki-Miyaura functionalization of N-trifluoromethylsulfaneylidene sulfoximine could be achieved depending on the conditions, resulting in coupling products with or without an introduced sulfoxide moiety. Sonogashira coupling of N-trifluoromethylsulfaneylidene sulfoximine furnished the expected acetylene derivative in high yield, and the reaction conditions are compatible with the newly introduced sulfaneylidene functionality. Bromine and nickel catalysts were also shown to be deprotecting agents of the sulfoxide group. A selected N-trifluoromethylsulfaneylidene sulfoximine demonstrated its stability in water in the presence of air and in dilute hydrochloric acid, while it converted back to the parent sulfoximine under basic conditions.

NIS-initiated photo-induced oxidative decarboxylative sulfoximidation of cinnamic acids

N-Iodosuccinimide catalyzed, visible-light-induced oxidative decarboxylative cross-coupling between cinnamic acids and NH-sulfoximines is presented. This strategy results in the formation of α-keto-N-acyl sulfoximines via the construction of two new CO bonds and one C-N bond. The in situ-generated N-iodosulfoximine serves as the light-absorbing species in the absence of any external photosensitizer. The keto carbonyl and amidic carbonyl oxygen in the resulting product originate from dioxygen and water respectively.

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.

Visible light-promoted NH-halogenation of sulfoximines with dichloromethane or dibromomethane

In the presence of a hypervalent iodine reagent, N-halo sulfoximines are obtained by catalyst-free visible light-promoted halogenations of their NH-counterparts with dichloro- or dibromomethane as halogen source.