Palladium/benzoic acid-catalyzed hydroalkoxylation of alkynes

✍ Scribed by Isao Kadota; Leopold Mpaka Lutete; Akinori Shibuya; Yoshinori Yamamoto

• Book ID: 104231264
• Publisher: Elsevier Science
• Year: 2001
• Tongue: French
• Weight: 68 KB
• Volume: 42
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)01207-2

✦ Synopsis

The reaction of the internal alkyne 1 with alcohols 2 in the presence of a catalytic amount of Pd(PPh 3 ) 4 and benzoic acid in dioxane at 100°C gave the allylic ethers 3 in good to high yields. The reaction proceeds via the palladium/benzoic acid-catalyzed isomerization of the alkyne 1 to allene 6, followed by the addition of alcohols 2 to the p-allylpalladium intermediate 7 formed by the hydropalladation of the resulting allene 6. Furthermore, the intramolecular reaction of alkynes having a hydroxy group at the terminus of the carbon chain gave five-and six-membered cyclic ethers in good yields.