Palladium-catalyzed cyclization reactions of propargylic carbonates with nucleophiles: a methodology for the syntheses of substituted 2,3-dihydrofurans and benzofurans
by the palladium-catalyzed reaction of 5-methoxycarbonyloxy-3-pentyn-1-ol with phenols. The propargylic carbonate containing a nucleophilicphenoxy group also reacted in the presence of palladium to produce the product. The reaction of 1-(2-hydroxyphenyl)-3-methoxycarbonyloxy-1-propyne with 2-methyl-1,3-cyclohexanedione or 2-methyl-1,3-cycohexanedione yielded the substituted benzofurans. The propargylic
Substituted 2,3-dihydrofurans and benzofurans are synthesized by the palladium-catalyzed reaction of 5-methoxycarbonyloxy-3-pentyn-1-ols and 1-(2-hydroxyphenyl)-3-methoxycarbonyloxy-1-propyne with nucleophiles, respectively. Various substituted propargylic carbonates and nucleophiles are efficiently transformed to their corresponding products. Additionally, a reaction using substrates containing a