Sodium Dithionite‐Mediated Decarboxylative Sulfonylation: Facile Access to Tertiary Sulfones

Abstract

A straightforward multicomponent decarboxylative cross coupling of redox‐active esters (N‐hydroxyphthalimide ester), sodium dithionite, and electrophiles was established to construct sterically bulky sulfones. The inorganic salt sodium dithionite not only served as the sulfur dioxide source, but also acted as an efficient radical initiator for the decarboxylation. Notably, diverse naturally abundant carboxylic acids and artificially prepared carboxyl‐containing drugs with multiple heteroatoms and sensitive functional groups successfully underwent this decarboxylative sulfonylation to provide sterically bulky tertiary sulfones. Mechanistic studies further demonstrated that decarboxylation was the rate‐determining step and occurred via a single‐electron transfer (SET) process with the assistance of sodium dithionite.

Accessing chiral sulfones bearing quaternary carbon stereocenters via photoinduced radical sulfur dioxide insertion and Truce–Smiles rearrangement

“…In view of its unique potential as single-electron reductant 55 , sodium dithionite was employed as the sulfur dioxide surrogate in combination with diazonium salts in our initial design to generate sulfonyl radicals for initiating the rearrangement. Using N -arylsulfinyl acrylamide 1a and aryldiazonium salt 2a as model substrates, we commenced the search for suitable reaction conditions with the corresponding results outlined in Table 1 .…”

Manganese-mediated reductive functionalization of activated aliphatic acids and primary amines

“…For this purpose, one feasible way is to activate the carboxylic acids and alkyl primary amines to the corresponding redox-active esters (RAE) and Katritzky's N-alkylpyridinium salts, respectively 16,17 . Previous studies demonstrated that both RAE [18][19][20][21][22][23][24][25][26][27][28] and Katritzky's salts [29][30][31][32][33][34][35][36][37] are predisposed to accept an electron from low-valent transition metals or organic Lewis bases under photocatalytic reaction conditions, thereby acting as precursors to the corresponding alkyl radicals (Fig. 1b) [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] .…”

Recent Advances in Asymmetric Organomulticatalysis

“…Thus, it can recognize the non‐ionic nitroolefin 115 [66d–h] through the H‐bond interaction to control the enantioselectivity. The catalyst of 2,6‐lutidine as Brønsted base can deprotonate the acidic nucleophile of thiol 116 , and then leading to realizing the asymmetric sulfa‐Michael addition and affording the desired sufide 117 [66i–t] . The diverse derivatization finally transfers the sulfide 117 to the bioactive molecules of taurine derivative 118 and 4‐monosubstituted β ‐sultam 119 .…”