Microwave-Accelerated N-Acylation of Sulfoximines with Aldehydes under Catalyst-Free Conditions

Abstract

An efficient catalyst-free radical cross-coupling reaction between aromatic aldehydes and sulfoximines was developed. The reaction took place in the presence of N-bromosuccinimide as the radical initiator under microwave irradiation to afford the corresponding acylated sulfoximines in moderate to excellent yields (27 examples). This protocol proved to be rapid, easy to handle, and applicable to a broad scope of substrates.

Synthesis and Transformations of NH‐Sulfoximines

“…Interestingly, the acylation reaction on NH-sulfoximines with arylaldehydes can be otherwise performed upon microwave irradiation and in the presence of NBS, as recently reported by Naicker, Arvidsson and coworkers (Scheme 35, b). [105] A visible-light promoted method for the synthesis of Naroylsulfoximines 37 from aldehydes has been developed by Zeng. [106] First, S-methyl-S-phenylsulfoximine and p-nitrobenzaldehyde reacted in the presence of a mixture of oxidants TBHP/ K 2 S 2 O 8 under air at room temperature and upon irradiation with Chemistry-A European Journal simulated sunlight (xenon arc lamp), affording the desired Naroylsulfoximine 37 a in 80 % yield (Scheme 36).…”

“…Interestingly, the acylation reaction on NH‐sulfoximines with arylaldehydes can be otherwise performed upon microwave irradiation and in the presence of NBS, as recently reported by Naicker, Arvidsson and coworkers (Scheme 35 , b). [105] …”

Oxidation of N-trifluoromethylthio sulfoximines using NaOCl·5H2O

“…16 N -acylation of N -H-sulfoximines with thioacids in the presence of a photoredox catalyst could be accomplished under blue LED irradiation. 17 Similarly, the transformation of N -H sulfoximine with aryl aldehydes 18 or ketones 19 in the presence of NBS yielded the corresponding N -acyl derivatives. The introduction of a halogen atom 20 or a halogenated moiety 21 produced various interesting sulfoximines.…”

Electrochemical N-acylation and N-α-ketoacylation of sulfoximines via the selective decarboxylation and dehydration of α-ketoacids

“…10 Naicker's group developed microwave-accelerated N -acylation of sulfoximines with aldehydes (Scheme 1-1b). 11 In recent years, visible-light-induced reactions have received widespread attention owing to their environmental compatibility and versatility. 12 For example, Bolm's group disclosed visible light-induced acylation of sulfoximines with ketones using NBS reagent (Scheme 1-1c).…”