Stereochemistry of intermolecular oxypalladation: Pd(II)-catalyzed 1,3-chirality transfer reaction of chiral allylic alcohol with methanol.
Stereochemistry of intermolecular oxypalladation: Pd(II)-catalyzed 1,3-chirality transfer reaction of chiral allylic alcohol with methanol.
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DOI：
10.1021/jo9011464
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发表时间：
2009-07
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影响因子：
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通讯作者：
Y. Vikhe;Sudhir M. Hande;N. Kawai;J. Uenishi
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文献类型：
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作者：
Y. Vikhe;Sudhir M. Hande;N. Kawai;J. Uenishi
手性非外消旋烯丙醇(S)-1、(R)-1和(R)-3在甲醇中的分子间氧化缩合反应得到了具有良好选择性的手性非外消旋烯丙基醚(S)-2和/或(R)-2。该反应诱导1，3-手性转移，通过SYN氧化缩合反应，完全生成SYN-S(N)2‘产物。另一方面，抗S(N)2‘的产物在四氢呋喃、甲苯和CH2Cl2中的生成率为20-33%，主要在CH3CN中生成。Pi-烯烃-钯络合物I和II被认为是解释合成和抗氧取代反应的重要中间体。副产物9由甲基烯丙基醚2经二次氧化缩合而成，但二次反应的速度比烯丙醇慢得多。
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-S(N)2' product exclusively through syn oxypalladation. On the other hand, the anti-S(N)2' product was produced in 20-33% in THF, toluene, and CH2Cl2 and predominantly in CH3CN. The pi-olefin-Pd complexes I and II are proposed as important intermediates to explain the syn- and anti-oxypalladation pathways. The byproduct 9 was formed through the second syn-oxypalladation from the methyl allyl ether 2, though the rate of this second reaction was far slower than that of allylic alcohol.