A Highly Efficient Route to Ferrocene Derivatives Containing Four-Carbon Heteroannular Bridges via a Novel Cyclization Reaction

Synthesis of 1,1′-bis((trimethylsilyl)ethynyl)-ferrocene and conversion of this compound to a ferrocene derivative containing a 1 -methoxy-1,3-butadienyl heteroannular bridging unit via a novel, catalytic, and high-yielding cyclization reaction are described. Simple synthetic transformations of this reactive bridging unit readily yield ferrocene derivatives containing four-carbon heteroannular bridges.