Olsson Vilhelm J, Sebelius Sara, Selander Nicklas, Szabó Kalman J
Department of Organic Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
J Am Chem Soc. 2006 Apr 12;128(14):4588-9. doi: 10.1021/ja060468n.
Allyl alcohols were converted to allyl boronic acids and subsequently to trifluoro(allyl)borates with tetrahydroxy diboron using palladium pincer-complex catalysis. These reactions are regio- and stereoselective proceeding with high isolated yields. Competitive boronation experiments indicate that under the applied reaction conditions the allylic displacement of a hydroxy group is faster than the displacement of an acetate leaving group. It is assumed that the hydroxy group of the allyl alcohol is converted to a diboronic acid ester functionality, which can easily be substituted.
烯丙醇通过钯钳形配合物催化,先转化为烯丙基硼酸,随后与四羟基二硼反应生成三氟(烯丙基)硼酸酯。这些反应具有区域和立体选择性,分离产率高。竞争性硼化实验表明,在所应用的反应条件下,烯丙醇羟基的烯丙基取代比乙酸酯离去基团的取代更快。据推测,烯丙醇的羟基转化为二硼酸酯官能团,该官能团易于被取代。