Allenes represent an extremely important class of organic molecules, which, as
a result of their twisted orthogonal π-systems can possess axial chirality. A wide array of
methods for allene synthesis have been reported, such as the substitution of propargylic
electrophiles, isomerization of alkynes and sigmatropic rearrangement. An alternative approach
for the synthesis of allenes is 1,2-elimination of an appropriately substituted precursor.
This mini-review highlights recent examples of 1,2-elimination processes, which
target allenes including both polar and radical processes. The main focus is upon how control
over the stereospecificity (e.g. syn- or anti-) of the 1,2-elimination process can enable
the synthesis of enantioenriched axially chiral allenes. Recent developments in this field
are presented including both enantiospecific and catalytic asymmetric methods.
Keywords: Allenes, cumulenes, elimination, stereospecific, enantiospecific, axial chirality.
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