Catalytic Regio- and Enantioselective Haloazidation of Allylic Alcohols

Herein
we report a highly regio- and stereoselective haloazidation
of allylic alcohols. This enantioselective reaction uses readily available
materials and can be performed on a variety of alkyl-substituted alkenes
and can incorporate either bromine or chlorine as the electrophilic
halogen component. Both halide and azido groups of the resulting products
can be transformed into valuable building blocks with complete stereospecificity.
The first example of an enantioselective 1,4-haloazidation of a conjugated
diene is reported as well as its application to a concise synthesis
of an aza-sugar.