As part of ongoing studies into the identification of new methods for the formation of nitrogen substituted stereocentres, we have developed efficient Narasaka-Heck cyclisations involving cyclic alkenes. The chemistry is reliant upon the use of an electron deficient, fluorinated phosphine ligand and provides access to versatile N-heterobicyclic scaffolds. These diastereoselective processes employ oxime ester starting materials that are easily accessed in enantiopure form.
More recently, we have extended our protocol to cyclisations involving 1,1-disubstituted alkenes. This provides direct access to molecules containing challenging quaternary amino-substituted stereocentres. Preliminary studies show that catalytic asymmetric variants of this chemistry are possible by using suitable chiral phosphine ligands.