A recently published paper by the Aponick Group is featured on the JACS website. The work, entitled “Enantioselective Alkyne Conjugate Addition Enabled by Readily Tuned Atropisomeric P,N-Ligands” describes how moving from the traditional 6-membered atropisomeric biaryl ligand architecture to chiral biaryl ligands containing a 5-membered heterocycle facilitates tuning. By the nature of the scaffold structure, ligand congeners are readily prepared, enabling one to address issues of selectivity and reactivity.
As an illustrative example, co-workers Sourabh Mishra and Ji Liu reported several novel ligands and identified Me-StackPhos as optimal for the enantioselective, direct conjugate addition of alkynes to ?,?-unsaturated Meldrum’s acids. The reaction scope was quite broad, allowing them to use this as a key reaction in the synthesis of OPC 51803, a pre-clinical agent that had previously only been prepared via classical resolution of off-path intermediates.
For more information, see the article at: http://pubs.acs.org/doi/abs/10.1021/jacs.7b00363