Enantioselective Cycloisomerization of 1,5-Enynes Promoted by Cyclometalated NHC-PtII-Monophos Catalysts

The enantioselective cycloisomerizations of 1,5-enynes bearing non-migrating oxygen functions at the propargylic carbon atom have been carried out by using MonophosPtII and BinepinePtII complexes as chiral precatalysts. They afforded the corresponding bicyclo[3.1.0]hexan-3-one in up to 63?% enantiomeric excess. The stereochemical outcome of these reactions has been investigated in order to highlight possible matchingmismatching effects between the chiral catalyst and chiral substrates with opposite configurations at the stereogenic carbon. A substantial effect of the stereogenic carbon has been evidenced.