Organocatalytic Asymmetric Sulfa‐Michael Additions to α,β‐Unsaturated Sulfonates

Abstract

The reactivity of α,β-unsaturated sulfonates and aromatic thiols in an organocatalyzed sulfa-Michael addition was explored. Bifunctional chiral thiourea catalysts were found to promote the reaction, and the corresponding Michael adducts were afforded in moderate to good yields (24-92 %)

Development of a Mild Procedure for the Addition of Bisulfite to Electrophilic Olefins

“…[11] The same group reported an organocatalytic-mediated addition of a sulfur nucleophile to a,b-unsaturated sulfonic acid esters. [12] Despite all these efforts, the simple addition of bisulfite to olefins, discovered over a century ago, [13] still remains the most straight-forward access to aliphatic sulfonic acids. This reaction employs large excesses of reactants and requires high temperatures.…”

Sensitisation of the Near‐Infrared Emission of NdIII from the Singlet State of Porphyrins Bearing Four 8‐Hydroxyquinolinylamide Chelates

“…Enders and co‐workers have reported the α‐alkylation of sulfonic acid esters with alkyl halides or with β‐nitroalkenes using a chiral auxiliary strategy10 and the nucleophilic addition of chiral nitrogen nucleophiles such as ( S )‐1‐amino‐2‐methoxymethylpyrrolidine (SAMP) to α,β‐unsaturated sulfonic acid esters 11. The same group reported an organocatalytic‐mediated addition of a sulfur nucleophile to α,β‐unsaturated sulfonic acid esters 12. Despite all these efforts, the simple addition of bisulfite to olefins, discovered over a century ago,13 still remains the most straight‐forward access to aliphatic sulfonic acids.…”

Catalytic Enantioselective Addition of Sodium Bisulfite to Chalcones

“…reported a few enantiopure sulfonic acids 2 , obtained from chalcones, as resolving agents5 by a “Dutch Resolution” approach 6. Several multistep syntheses of chiral sulfonic acids have been reported 7–11. However, the simple addition of bisulfite to olefins, discovered over a century ago,12 remains the most straightforward access to aliphatic sulfonic acids.…”