ALKYNE HYDRATION USING PT(II) CATALYSTS

A series of Pt(II) derivatives has been found to be quite effective as alkyne hydration catalysts. These are new and differ from many other hydration catalysts in that there is no need to add protonic acids to or as the media. They are effective for hydration of electron rich alk ynes but not useful for electron deficient systems. Finally, using uns ymmetrically substituted alkynes, slight regioselectivity is observed with the carbonyl moiety preferring the position closer to the bulky s ubstituent. When substituents have heteroatoms such as oxygen or sulfu r, a chelation control process seems to govern the regiochemistry and high selectivities may be obtained.