Stereochemistry of Intermolecular Oxypalladation: Pd<sup>II</sup>-Catalyzed 1,3-Chirality Transfer Reaction of Chiral Allylic Alcohol with Methanol
作者:Yogesh S. Vikhe、Sudhir M. Hande、Nobuyuki Kawai、Jun’ichi Uenishi
DOI:10.1021/jo9011464
日期:2009.8.7
The intermolecular oxypalladation of chiral nonracemic allylic alcohols (S)-1, (R)-1, and (R)-3 in methanol gave chiral nonracemic methyl allyl ethers (S)-2 and/or (R)-2 with excellent selectivity. The reaction induced the 1,3-chirality transfer to give syn-SN2′ product exclusively through syn oxypalladation. On the other hand, the anti-SN2′ product was produced in 20−33% in THF, toluene, and CH2Cl2
手性非外消旋烯丙基醇(S -1),(R)-1和(R)-3在甲醇中的分子间氧化palpalpalation得到具有优异选择性的手性非外消旋甲基烯丙基醚(S)-2和/或(R)-2。反应引起的1,3-手性转移,得到顺式-S Ñ只通过2'产物顺oxypalladation。另一方面,抗-S N 2'产物在THF,甲苯和CH 2 Cl 2中的生成率为20-33%并主要存在于CH 3 CN中 提议将π-烯烃-Pd配合物I和II作为重要的中间体,以解释合成-和抗-氧化palpalation途径。副产物9通过第二形成顺式从甲基烯丙基醚-oxypalladation 2,尽管该第二反应的速率远远慢于该烯丙醇。