Synthesis of 3-amino-substituted benzothiadiazine oxides by a palladium-catalysed cascade reaction

Abstract

A variety of 3-amino-substituted benzothiadiazine oxides were synthesised in a single-step by applying a palladium-catalysed cascade reaction of 2-azido sulfoximines with isonitriles. The desired heterocycles were observed in good to...

Palladium‐Catalyzed Domino Reaction for the Synthesis of 3‐Amino 1,2,4‐Benzothiadiazine 1,1‐Dioxides

“…By applying literature‐known conditions, compound 3 aa was treated with HCl to test the viability of the envisaged dealkylation path (Scheme 4). [18,19a] To our delight, the desired free amine 6 a could be obtained in 74% yield. As by‐product, however, demethylated product 7 a was formed in 10% yield.…”

“…As part of our ongoing research on the synthesis of sulfur‐containing heterocycles, [19] we recently reported a highly efficient protocol for the synthesis of 3‐amino‐substituted benzothiadiazine oxides [19a] . When applying tetrakis(triphenylphosphine) palladium(0) in catalyst loadings of 0.25–1.5 mol%, 2‐azidosulfoximines reacted with isocyanides to the corresponding heterocycles under ambient conditions and in short reaction times.…”

“…The investigations were started by applying the previously developed protocol [19a,20] in the model reaction of 2‐azidobenzenesulfonamide 1 a with isocyanide 2 a and tetrakis(triphenylphosphine)‐palladium(0) as a metal pre‐catalyst (Table 1, entry 1). To our delight, our initial hypothesis was correct, and compound 3 aa was isolated in 29% yield.…”

“…Finally, we decided to investigate the reaction mechanism. Based on previous studies [19a,20b] we propose a domino reaction sequence involving the formation of a carbodiimide as a potential key intermediate. To test this hypothesis, the reaction of Boc‐protected 2‐azido sulfonamide 8 with model isocyanide 2 a was investigated (Scheme 5).…”

Visible-light-induced iron-catalyzed S–N cross-coupling of thiols with dioxazolones

“…Sulfur–nitrogen bonds are ubiquitous in nature, and they play a vital role in medicinal and pharmacological chemistry due to their fascinating bioactive properties. 1,2 N -Acylsulfenamides, 3 a class of compounds featuring S–N bonds, are widely utilized in agrochemicals (captan and phaltan) and polymer applications. Recently, these compounds have received significant interest in medicinal chemistry because of their potential applicability as prodrugs for N–H acid compounds such as amides, carbamates, and ureas (Scheme 1).…”