14 research outputs found
Computationally Guided Design of a Readily Assembled Phosphite- Thioether Ligand for a Broad Range of Pd-Catalyzed Asymmetric Allylic Substitutions
A modular
approach employing indene as common starting material,
has enabled the straightforward preparation in three reaction steps
of P-thioether ligands for the Pd-catalyzed asymmetric allylic substitution.
The analysis of a starting library of P-thioether ligands based on
rational design and theoretical calculations has led to the discovery
of an optimized anthracenethiol derivative with excellent behavior
in the reaction of choice. Improving most approaches reported to date,
this ligand presents a broad substrate and nucleophile scope. Excellent
enantioselectivities have been achieved for a range of linear and
cyclic allylic substrates using a large number of C-, N-, and O-nucleophiles
(40 compounds in total). The species responsible for the catalytic
activity have been further investigated by NMR in order to clearly
establish the origin of the enantioselectivity. The resulting products
have been derivatized by means of ring-closing metathesis or Pauson–Khand
reactions to further prove the synthetic versatility of the methodology
for preparing enantiopure complex structures