Eisold M.
Didier D.
* Ludwig-Maximilians-Universität München, Germany
Stereoselective Access to Alkylidenecyclobutanes through γ-Selective Cross-Coupling
Strategies.
Org. Lett. 2017;
19: 4046-4049
Key words
palladium catalysis - alkylidenecyclo-butanes - γ-selective cross-coupling
Significance
Alkylidenecyclobutanes are useful strained building blocks that can also be found
in a number of natural compounds. In this work, the authors disclose the use of a
γ-selective Suzuki–Miyaura cross-coupling for the synthesis of this class of compounds
containing a quaternary stereocenter.
Comment
Achiral cyclobutenylmethylboronic esters reacted with aryl halides in the presence
of a palladium catalyst and potassium hydroxide. The corresponding products were obtained
in moderate to excellent yields and essentially with perfect γ-selectivity. In the
case of δ-substituted substrates, high levels of diastereoselectivity were obtained.
The use of (chiral) α-substituted starting materials generated the corresponding products
containing a trisubstituted double bond functionality in high stereoselectivity (and
enantioselectivity).
