BINAP versus BINAP(O) in asymmetric intermolecular Mizoroki-Heck reactions: substantial effects on selectivities

2,2′‐Bis(diphenylphosphino)‐1,1′‐binaphthyl (BINAP) was employed as chiral ligand in the enantioselective intermolecular Mizoroki–Heck reaction, whereas the use of cognate BINAP(O) (monooxidized BINAP) is unprecedented. The regio‐ and enantioselectivity of the arylation of representative cyclic alkenes changes dramatically in the presence of hemilabile BINAP(O) instead of BINAP. The arylation of 2,3‐dihydrofuran is perfectly regiodivergent (98:2 versus 0:100) and the arylation of cyclopentene is only enantioselective with BINAP(O) 60 versus 10 % enantiomeric excess (ee)]. Use of Pd₂(dba)₃] ? dba (dba=dibenzylideneacetone) instead of Pd(OAc)₂ produces as high as 86 % ee in the arylation of cyclopentene.