Copper-Catalyzed Intermolecular Asymmetric Transformations of Vinyl Cations via [1,2]-Stevens-Type Rearrangement

Significant advancements have been achieved in the formation
of
organic sulfides via the [1,2]-Stevens-type rearrangement reaction
of sulfur ylides, but the corresponding asymmetric version has been
scarcely reported to date. Furthermore, the limited existing results
predominantly rely on using diazo compounds as precursors with a limited
substrate scope and unsatisfactory enantioselectivity. Herein, we
report an efficient asymmetric [1,2]-Stevens rearrangement via vinyl
cations by copper-catalyzed diyne cyclization, enabling practical,
atom-economical, and divergent access to various chiral S-heterocycles
containing two consecutive stereocenters with moderate to high yields
and high stereocontrols. Importantly, this protocol features an intermolecular
catalytic asymmetric [1,2]-Stevens rearrangement by a nondiazo pathway,
and constitutes an asymmetric [1,2]-Stevens rearrangement of 1,3-dithiolanes
and thiazolidines.