Asymmetric cyclopentannelation: Camphor-derived auxiliary
Asymmetric cyclopentannelation: Camphor-derived auxiliary
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DOI：
10.1021/ja020591o
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发表时间：
2002-08-28
影响因子：
15
通讯作者：
Tius, MA
中科院分区：
文献类型：
--
作者：
Harrington, PE;Murai, T;Tius, MA
探索了利用联烯基醚衍生的亲核试剂进行环戊烷缩酮的对映选择性反应的范围。对映体选择性是由一种易于从樟脑衍生的无痕手性助剂诱导的。已经表明，对于轴向手性的γ-取代的丙二烯醚，在匹配的情况下观察到环戊烯酮产物的非常高的对映体过量。观察到两种根本不同的机制，一种用于丙二烯基酮的环化（参见等式7），另一种用于丙二烯基醇的环化（参见等式11）。该方法是通用的，高效的，非常适合于合成中的应用。
The scope of an enantioselective cyclopentannelation reaction that makes use of allenyl ether-derived nucleophiles has been probed. The enantioselectivity is induced by a traceless chiral auxiliary that is easily derived from camphor. It has been shown that for gamma-substituted allene ethers that are axially chiral, very high enantiomeric excesses of cyclopentenone products are observed in the matched cases. Two fundamentally different mechanisms are observed, one for the cyclizations of allenyl ketones (see eq 7), the other for the cyclizations of allenyl alcohols (see eq 11). The methodology is versatile, efficient, and well-suited for applications in synthesis.