Cyclobutane and cyclobutene synthesis: catalytic enantioselective [2+2] cycloadditions.
Cyclobutanes and cyclobutenes are important structural motifs found in numerous biologically significant molecules, and they are useful intermediates for chemical synthesis. Consequently, [2+2] cycloadditions to access cyclobutanes and cyclobutenes have been established to be particularly useful transformations. Within the last 10 years, an increase in the frequency of publications for catalytic enantioselective [2+2] cycloadditions has occurred. These reactions provide access to a wide array of enantiomerically enriched chemical diversity that was not previously attainable. Described in this review are the advances made in catalytic enantioselective [2+2] cycloadditions to access cyclobutanes and cyclobutenes.
Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47405 (USA).
Yao
Y
Xu
Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47405 (USA).
Michael L
ML
Conner
Department of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, IN 47405 (USA). brownmkb@indiana.edu.
M Kevin
MK
Brown
alkenes; cycloaddition; enantioselectivity; small-ring systems; synthetic methods