Intramolecular Pd-Catalyzed Carboetherification and Carboamination

Significance

The authors describe a diastereoselective carboetherification and carboamination protocol generating two attached five-membered rings. The relative stereochemistry generated in the THF products can be controlled by starting alkene stereochemistry or by changing the ligand on palladium. Use of bidentate ligands (i.e. BINAP, DPPE) form products derived from an anti-addition pathway, whereas the use of monodentate phosphines generates products stemming from a syn-addition pathway. One main explanation for what the authors believe are different operating mechanisms is the reactivity of a 16-electron intermediate (monodentate phosphine ligated Pd) versus an 18-electron intermediate (bidentate phosphine ligated Pd).