[3+2] Cycloaddition of Phenyliodonium Bis(arylsulfonyl)methylides with α,β-Enones

The [3+2] cycloaddition of phenyliodonium bis(arylsulfonyl)methylides to α,β-enones affords exclusively TRANS, TRANS-configured 1-(arylsulfonyl)-2-aroyl-3-arylindanes. The initial electrophilic attack of the iodonium ylide on the alkenyl double bond of the chalcone, followed by cyclization of the dipolar species, and subsequent ejection of iodobenzene and sulfur dioxide, stereoselectively affords the indane cycloadduct.