Chemical Chameleons. Organosulfones as Synthetic Building Blocks

Abstract

Abstract An overview of the duality of function of organosulfones as nucleophiles in basic media and electrophiles in Lewis acidic media, a change of reactivity for which they have been dubbed “chemical chameleons,” is presented. In the first phase, transition metal catalysts activate allyl sulfones towards displacements. Use of palladium, molybdenum, and nickel catalysts allow stabilized anions to effect displacement; copper catalysts allow non-stabilized nucleophiles to be used. The use of the anion stabilizing and leaving group abilities of sulfones created a novel three carbon intercalation and a novel cyclocontraction-spiroannulation in which β-hydroxy sulfones participate in a Lewis acid catalyzed pinacol rearrangement. The lability of allyl and tertiary sulfones towards Lewis acids creates a wide array of electrophilic reactions such as Friedel–Crafts type cyclizations, intermolecular alkylations with organoalanes and enol silyl ethers, and ring expansions. The ability to design novel reagents for synthesis based upon this dual reactivity of organosulfones is illustrated by the use of an alkoxy-bis(phenylsulfonyl)methane as a synthon for a carbonyl 1,1-dipole.