Sequential-Flow Synthesis of Donepezil: A Green and Sustainable Strategy Featuring Heterogeneous Catalysis and Hydrogenation.

An atom-economical sequential-flow synthesis of donepezil, a widely prescribed drug for Alzheimer's disease, was accomplished using inexpensive, commercially available precursors. This achievement was made possible by reconfiguring the synthetic route to include only heterogeneous catalytic addition and condensation reactions, with a particular emphasis on skeletal transformation and bond formation through hydrogenation processes. Notably, water was the sole byproduct in this synthesis.

Re(I)-Catalyzed Hydropropargylation of Silyl Enol Ethers Utilizing Dynamic Interconversion of Vinylidene-Alkenylmetal Intermediates via 1,5-Hydride Transfer.

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.

Rhenium(I)-Catalyzed Generation of α,β-Unsaturated Carbene Complex Intermediates from Propargyl Ethers for the Preparation of Cycloheptadiene Derivatives.

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.