Reactivity series for s-BuLi/diamine-mediated lithiation of N-Boc pyrrolidine: applications in catalysis and lithiation of N-Boc piperidine.
Using competition experiments between a range of ligands and (-)-sparteine, a reactivity series for N-Boc pyrrolidine lithiation using s-BuLi/diamines has been constructed; the results indicate that the s-BuLi/(+)-sparteine surrogate complex is more reactive than s-BuLi/(-)-sparteine and this has been exploited in the selection of ligand pairs for ligand exchange catalytic asymmetric lithiation of N-Boc pyrrolidine and lithiation of N-Boc piperidine.
McGrath
Matthew J
MJ
Department of Chemistry, University of York, Heslington, York, UK YO10 5DD.
Bilke
Julia L
JL
O'Brien
Peter
P