The rhenium(I)-catalyzed generation of α,β-unsaturated carbene complex intermediates from easily available propargyl ethers was achieved for the concise construction of cycloheptadiene derivatives through the formal [4+3] cycloaddition reaction with siloxydienes.

Re(I)-catalyzed hydropropargylation reaction of silyl enol ethers was realized utilizing dynamic interconversion of vinylidene-alkenylmetal intermediates, where alkenylmetals underwent 1,5-hydride transfer of the α-hydrogen to generate vinylidene intermediates. Furthermore, this process was found to be in an equilibrium.

The rhenium(I)‐catalyzed generation of α,β‐unsaturated carbene complex intermediates from easily available propargyl ethers was achieved for the concise construction of cycloheptadiene derivatives through the formal [4+3] cycloaddition reaction with siloxydienes.

Platinum(II)-catalyzed intermolecular formal [4+3]-cycloaddition reaction of α,β-unsaturated carbene complex intermediates with siloxydienes proceeded under mild conditions to give cyclohepta [b]indole derivatives in good yield. The reaction was found to proceed via 1,2-alkyl shift of the carbene complex intermediates obtained by [4+2]-cycloaddition reaction of the unsaturated carbenes with dienes.

The rhenium(I)‐catalyzed generation of αβ‐unsaturated carbene complex intermediates from easily available propargyl ethers is achieved for the concise construction of cycloheptadiene derivatives through the formal [4+3] cycloaddition reaction with siloxydienes.