An "anti-Baldwin" 3-exo-dig cyclization: preparation of vinylidene cyclopropanes from electron-poor alkenes.
Stabilized carbanions undergo an uncommon 3-exodig cyclization onto propargyl halides through an SN2' substitution. Propargyl iodides as electrophiles are necessary to achieve good yields (36-95%) for most substrates, although the usefulness of chlorides and bromides is documented. A variety of monocyclic and bicyclic vinylidene cyclopropanes can be prepared. These products are not available by standard carbene methodology.
Campbell
Matthew J
MJ
Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
Pohlhaus
Patrick D
PD
Min
Geanna
G
Ohmatsu
Kohsuke
K
Johnson
Jeffrey S
JS