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

Abstract

The sulfonylation of activated alkenes is an important yet unexplored reaction due to the harshness of conditions required. We have identi- fied a procedure which allowed the reaction of al- kenes with equimolar amounts of bisulfite at room temperature

Catalytic Enantioselective Addition of Sodium Bisulfite to Chalcones

“…[%] [ The catalysis displayed by organic bases [14] prompted us to explore the effect of enantiopure amines on the addition of bisulfite to alkenes. Preliminary studies indicated that 1.0 equivalent of (À)-sparteine, (À)-ephedrine, (À)-diphenylprolinol, or quinine promoted the addition of bisulfite to 1 a, giving sulfonic acid 2 a in low enantioselectivity (9-30 % ee).…”

“…[5,13] We have recently shown that 1) decreasing the concentration of bisulfite and 2) employing organic base catalysis can increase the rate of addition of bisulfite to electrophilic alkenes. [14] Careful adjustment of these conditions resulted in a mild protocol for the addition of bisulfite to electrophilic alkenes. [14] Scheme 1.…”

“…[14] Careful adjustment of these conditions resulted in a mild protocol for the addition of bisulfite to electrophilic alkenes. [14] Scheme 1. Enantioselective addition of bisulfite to chalcones.…”

Cyclopropanation of 5-(1-Bromo-2-phenyl-vinyl)-3-methyl-4-nitro-isoxazoles under Phase Transfer Catalysis (PTC) Conditions

“…Furthermore, compounds 1 have two electrophilic centers that can be selectively reacted. Enolates, which are stabilized soft nucleophiles, react at the soft electrophilic center E2, whereas hard nucleophiles such as hydroxide react exclusively at the hard electrophilic center E1 ( Figure 1) [1][2][3][4][5][6][7][8][9][12][13][14].…”

“…3-Methyl-4-Nitro-5-styrylisoxazoles 1 [1][2][3][4][5][6][7][8][9] and 2 [3] (Scheme 1) represent two types of polyfunctional scaffold which hold excellent potential for the generation of diversity ( Figure 1) [1][2][3][4][5][6][7][8][9]. Compounds 1 and 2 can be readily prepared from commercially available 3,5-dimethyl-4-nitroisoxazole 3 and aromatic aldehydes 4 ( Figure 1) [10].…”