Highly stereoselective synthesis of functionalized β,β-Di- and trisubstituted vinylic sulfoxides by Cu-catalyzed conjugate addition of organozinc reagents

beta,beta-Disubstituted chiral vinylic sulfoxides bearing functionalities have been synthesized via Cu-catalyzed conjugate addition of organozinc reagents to chiral 1-alkynyl sulfoxides. Due to the availability of functionalized organozinc reagents and high syn-selectivity of the reaction, both geometric beta,beta-disubstituted vinylic sulfoxides were selectively synthesized. Furthermore, 1-alkynyl sulfoxides were derivatized into trisubstituted vinylic sulfoxides by trapping the resulting alpha-sulfinyl vinylic carbanion with electrophiles. Highly diastereoselective THF and THP ring formations were accomplished by means of this methodology followed by an intramolecular Michael addition.