The Cyclopentadienyl-Osmium Moiety as Template for the Formation of a Dihydronaphthylphosphine by Coupling between Phenylacetylene and an α-Alkenylphosphine

Complex Os(η5-C5H5)(C⋮CPh){[η2-CH2C(CH3)]PiPr2} (1) reacts with HBF4·OEt2 to give the
π-alkyne derivative [Os(η5-C5H5)(η2-HC⋮CPh){[η2-CH2C(CH3)]PiPr2}]BF4 (2), which is transformed to [Os(η5-C5H5)(1,2-dihydro-2-methylnaphth-2-yldiisopropylphosphine)]BF4 (3) as a result of the coupling of the alkyne
with the isopropenyl substituent of the starting phosphine. The tridentate coordination mode of the dihydronaphthylphosphine in 3 is proved by X-ray diffraction
analysis.