Efficient Domino Process Based on the Catalytic Generation of Non-Metalated,Conjugated Acetylides in the Presence of Aldehydes or Activated Ketones

摘要

The extremely mild and highly efficient atalytic generation of nonmetalated conjugated acetylides is reported These acetylides are used to generate enol-protected functionalized propargylic alcohols 1 1,3-dioxolane compounds 2, or 3,4,5-trisubstituted 4,5-dihydrofurans 4 through serial multibond-forming processes The method cals for a nuclephile (a tertiary amine or phosphine) as a chemical activator a conjugated terminal acetylene as the acetylide source and an aldehyde or activated ketone as the electrophilic partaner The chemical outcome of this process depends on the nature of the nucleophile the temperature stoichiometry and solvent and it can be tailored selectivelyi by the appropriate choice of the experimental conditions.