Design and Applications of a SO₂ Surrogate in Palladium‐Catalyzed Direct Aminosulfonylation between Aryl Iodides and Amines

Abstract

Anew SO 2 surrogate is reported that is cheap,benchstable,a nd can be accessed in just two steps from bulk chemicals.E ssentially complete SO 2 release is achieved in 5minutes.Eight established sulfonylation reactions proceeded smoothly by ex situ formation of SO 2 by utilizing at wochamber system in combination with the SO 2 surrogate. Furthermore,w er eport the first direct aminosulfonylation between aryl iodides and amines.B road functional group tolerance is demonstrated, and the method is applicable to pharmaceutically relevant substrates,i ncluding heterocyclic substrates.

Metal- and Base-Free C(sp2)–H Arylsulfonylation of Enamides for Synthesis of (E)-β-Amidovinyl Sulfones via the Insertion of Sulfur Dioxide

“…Recently, our group designed a cheap, solid, and bench-stable SO 2 surrogate (SOgen) which was successfully applied in Pd-catalyzed direct aminosulfonylation of aryl iodides and amines . Herein, we demonstrate a transition-metal- and base-free C­(sp 2 )–H direct arylsulfonylation of secondary and tertiary enamides with aryl diazonium salts and SOgen (Figure d) This method proceeds smoothly and exhibits excellent stereoselectivities to produce geometrically defined ( E )-β-amidovinyl sulfones in moderate to good yields.…”

Multicomponent reactions and photo/electrochemistry join forces: atom economy meets energy efficiency

“…Among all, the most used in photoredox-catalyzed reactions are DABSO (1,4-diazabicyclo[2.2.2]octane-bis(sulfur dioxide) adduct), sodium and potassium metabisulfite (NaS 2 O 5 , KS 2 O 5 ) and the recently introduced SOgen. 262 The first has observed wide employment as a convenient source of 2 equivalents of SO 2 , but its widespread utilization is hindered by the cost of the commercially available reagent and its poor solubility in many organic solvents. Its poor atom economy, due to the release of DABCO as waste, has also led to the employment of metabisulfites instead, but similar solubility problems in organic solvents occur.…”

Advances in photochemical and electrochemical incorporation of sulfur dioxide for the synthesis of value-added compounds

“…of SO 2 ex-situ in a two-compartment system at elevated temperature. 25 Although this system has been well-proven in various transformations, the atom economy is very low. Alternatively, SO 2 can be generated ex-situ from Na 2 SO 3 and sulfuric acid with subsequent gas introduction into the reaction mixture.…”

“…Alternatively, SO 2 can be oxidized electrocatalytically to SO 3 on Co phthalocyanines with gas diffusion electrodes. 22 Currently, there is intense research interest in sulfur chemistry and the direct incorporation of SO 2 into organic molecules, 18,23,[24][25][26][27][28][29][30][31][32][33][34][35] which is originated in the broad bioactivity of sulfur-containing molecules making them extraordinarily interesting in drug discovery, agrochemicals, and medicinal chemistry. 24,36 Among, the different approaches, radical processes are especially well-suited for the direct fixation of SO 2 .…”