通过有机子方法学催化不对称合成棕甲酸A
Marlin Penner1, Vivek Rauniyar, Ludwig T Kaspar
1Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada.
Journal of the American Chemical Society
|September 22, 2009
概括
研究人员实现了海洋天然产品 (-) - 棕胺 A. 的催化酶选择合成. 这种新的方法避免了奇拉辅助器和奇拉池,为药物发现提供了一个新的策略.
科学领域:
- 有机化学 有机化学
- 自然产品的合成自然产品的合成
- 药用化学 医学化学
背景情况:
- 像 (-) -palmerolide A 这样的海洋天然产品显示出作为抗黑色素瘤剂的前途.
- 有效和酶选择性合成途径对于获得这些复杂分子以进一步研究和药物开发至关重要.
- 现有的合成策略可能是漫长的或依赖于不太可持续的方法.
研究的目的:
- 开发一种新型的,催化式对 (-) - - 棕甲基的选择性合成.
- 建立一个策略,避免静态测量性辅助器和性池.
- 探索适用于复杂天然产品目标的新合成方法.
主要方法:
- 采用了一个21步合成序列.
- 用一种新的克莱森-爱尔兰重新排列,使用基酸作为掩盖基组,用于分子的右半部分.
- 一种二醇.SnCl(4) 催化酶选择性基化在左半球复杂基合成中首次应用.
主要成果:
- 取得了 (-) - 棕甲基的成功催化酶选择合成.
- 合成证明了一个新的克莱森-爱尔兰重排变体的实用性.
- 这项研究首次展示了二醇.SnCl(4) 催化反选择性克罗提尔化在复杂合成中的应用.
结论:
- 已经建立了一个新的和高效的合成路径到 (-) -palmerolide A.
- 开发的战略为获得复杂的海洋自然产品提供了一个强大的工具.
- 这种独特的合成方法可能有助于设计简化,可能更强大的棕胺类同类物.
相关概念视频
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In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
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Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
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02:36Regioselectivity and Stereochemistry of Hydroboration
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