Platinum(0) - 1,3-Divinyltetramethyldisiloxane Complex (19.0-21.5% as Pt) (contains 1,3-Divinyltetramethyldisiloxane)

Experimental procedure: dimethyl-2-thienylsilane (32 mg, 0.22 mmol) is added dropwise to a solution of Karstedt catalyst (0.1 M in xylenes，9 µL，0.0009 mmol) and tert-Bu₃P (1 µL，0.003 mmol) in THF (0.7 mL), and the mixture is stirred for 30 min at rt. A solution of (E)-5-(tetrahydropyran-2-yloxy)pent-3-en-1-yne (30 mg，0.18 mmol) in THF (1 mL) is then added over 10 min and the reaction mixture is stirred for 10 h at rt. The solvent is removed under vacuum and the crude is purified by column chromatography (SiO₂, hexane/AcOEt) to afford 1 (92% yield).