The Addition of a Cyclopropyl Alkyne to an Asymmetrically-Substituted Disilene: A Mechanistic Study

The addition of (2-ethynyl-3-methoxy-2-methylcyclopropyl)benzene to Tip2Si═SiTipPh, a disilene with an asymmetric substitution pattern, was investigated. The regiochemistry of the ring-opened products indicates a stepwise mechanism with a biradical intermediate. The results are consistent with those obtained in similar experiments with symmetrically substituted disilenes.