Selective Synthesis of N-Cyano Sulfilimines by Dearomatizing Stable Thionium Ions

Abstract

For the selective synthesis of N-cyano sulfilimines, we have developed a new method based on the soft−soft interaction between thionium ion electrophiles and cyanonitrene nucleophiles. The stable thionium ion was successfully obtained by oxidative dearomatization using phenyliodine (III) diacetate (PIDA) in N,N-dimethylformamide (DMF). The sulfur imination reactions were tolerant to a wide range of functional groups and exhibited high selectivities and excellent yields. The existence of thionium ion intermediates was confirmed by ultraviolet/visible (UV/vis) spectroscopy and 1 H NMR experiments.

Acid-Catalyzed Hydrolysis and Intramolecular Cyclization of N-Cyano Sulfoximines for the Synthesis of Thiadiazine 1-Oxides

“…As following our previous study, imination of thioanisol derivatives 7 produced the corresponding N -cyano sulfilimines 8 in excellent yield. The subsequent oxidation of sulfilimines with m -CPBA provided the target N -cyano sulfoximine 9b–9i .…”

“…With a goal of enhanced simplicity and synthetic efficiency for the synthesis of thiadiazine 1-oxides 10 , we envisaged the one-pot acid-induced intramolecular cyclocondensation approach. Our previous finding of the thionium ion-mediated N -cyano sulfilimine 8 synthesis and the subsequent oxidation successfully provided the desired 2- N -cyano-sulfonimidoyl amides 9 (Figure b). It should be highlighted that the recent success in the imination of reactive functional group-substituted thioanisoles 7 has been used as the key step in the practical synthesis of thiadiazine 1-oxides 10 .…”

“…Our previous finding of the thionium ion-mediated N -cyano sulfilimine 8 synthesis and the subsequent oxidation successfully provided the desired 2- N -cyano-sulfonimidoyl amides 9 (Figure b). It should be highlighted that the recent success in the imination of reactive functional group-substituted thioanisoles 7 has been used as the key step in the practical synthesis of thiadiazine 1-oxides 10 . Mechanistically, this reaction is assumed to proceed via the intramolecular cyclization of N H sulfoximines, which is formed in situ by the acid-catalyzed hydrolysis of the N -cyano group…”

N-Cyano sulfilimine functional group as a nonclassical amide bond bioisostere in the design of a potent analogue to anthranilic diamide insecticide

“…In order to apply the aforementioned approach in our discovery program, we decided to study the N -cyano sulfilimine group-substituted chlorantraniliprole analog 1 based on our previous research. 49–52 As the reference molecule, chlorantraniliprole has captured a significant market share in the insect control business. This insecticide belong to the anthranilic diamide class of chemistry and provides excellent crop protection.…”

Conglomerate Crystallization in the CSD (2020–2021)

“…EYEMIH,35 OXACEY,36 TUDVAS,37 CUGXEK,38 UWOBUG, 39 CUYREW, 40 BUHZEM, 41 SUNKUK, 42 PUGQEQ, 43 UHECUI, 44 OMEXAI, 45 YUKNIE. 46 Further examples of conglomerate crystallization were observed to have occurred within the synthesis of natural products in this updated distribution of the CSD, as shown in Figure 4 (OWUREG, 49 XOLNIY, 50 and OCUGOM 51 ).…”