Synthesis of Difluoroalkyl Unsaturated β‑Amino Acid Derivatives Exclusively through Alkyne Difunctionalization

Alkynes difunctionalization is a
powerful strategy in organic synthesis
that provides a convenient synthetic entry for internal alkenes. The
main challenge in this field was considered to be the geometry control
of the newly formed double bond (thermodynamically controlled or kinetically
controlled). Herein, we report a novel procedure (through the cyclic
compounds broken) to completely control the regioselectivity of olefins.
The products, difluoroalkyl unsaturated β-amino acid derivatives,
have potential applications in some important pharmaceuticals on account
of the special nature of fluorine atoms.