Sulfones are a major class of organosulfur compounds that have been extensively used as versatile intermediates in organic synthesis. Cyclic sulfones have also been investigated as the key subunit and scaffold for the construction of biologically active molecules. The asymmetric synthesis of gem-diaryl substituted sulfamidates and sulfamides through the enantioselective addition of arylboronates to cyclic ketimines reported by rhodium–chiral diene complexes. The reaction of 3-sulfolene with arylboronic acids in the presence of a chiral diene-rhodium catalyst under highly basic conditions to prepare 3-arylsulfolanes was also reported. Here we report that cyclic sulfones (1-Benzothiophene-1,1-dioxide derivatives) are also good substrates leading to chiral 3-alkynylsulfones with high yield enantioselectivity through the rhodium-catalyzed asymmetric alkynylation by addition of (triisopropylsilyl)-acetylene and (R)-DTBM-Segphos as a ligand . In summary,we have developed a rhodium-catalyzed asymmetric alkylynation of cyclic sulfone compounds in high yields with high regioselectivity and high enantioselectivity.
