Meerwein-Ponndorf-Verley alkynylation of aldehydes: essential modification of aluminium alkoxides for rate acceleration and asymmetric synthesis.
Meerwein-Ponndorf-Verley alkynylation of aldehydes: essential modification of aluminium alkoxides for rate acceleration and asymmetric synthesis.
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醛的 Meerwein-Ponndorf-Verley 炔基化：对铝醇盐进行必要的改性，以实现速率加速和不对称合成。
DOI：
10.1039/b411090k
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发表时间：
2004
影响因子：
3.2
通讯作者：
K. Maruoka
中科院分区：
文献类型：
--
作者：
T. Ooi;T. Miura;K. Ohmatsu;A. Saito;K. Maruoka
利用Meerwein-Ponndorf-Verley（MPV）反应体系，完成了一种新的羰基炔基化反应。MPV炔基化的成功关键取决于2，2 '-联苯酚显著的配体加速效应的发现。例如，三氯乙醛（2c）与由Me（3）Al、2，2 '-联苯酚和作为炔基源的2-甲基-4-苯基-3-丁炔-2-醇（1a）原位制备的烷氧基铝6（R = Ph）的炔基化在室温下在CH（2）Cl（2）中顺利进行，在搅拌5小时后以几乎定量的产率得到所需的炔丙醇3ca。这种不涉及金属炔化物的新转化的特征可以通过以下事实来可视化：带有酮羰基的炔基成功地转移到醛羰基而没有任何酮羰基副反应。虽然（S）-1，1 [prime or minute]-联-2-萘酚及其简单类似物的使用被发现不适合于在该反应中诱导不对称性，但具有联苯轴的一定柔性的新手性联苯酚的设计在对映体选择性以及反应性方面导致令人满意的结果。
A novel carbonyl alkynylation has been accomplished based on utilization of the Meerwein-Ponndorf-Verley (MPV) reaction system. The success of the MPV alkynylation crucially depends on the discovery of the remarkable ligand acceleration effect of 2,2'-biphenol. For example, the alkynylation of chloral (2c) with the aluminium alkoxide 6(R = Ph), prepared in situ from Me(3)Al, 2,2'-biphenol and 2-methyl-4-phenyl-3-butyn-2-ol (1a) as an alkynyl source, proceeded smoothly in CH(2)Cl(2) at room temperature to give the desired propargyl alcohol 3ca in almost quantitative yield after 5 h stirring. The characteristic feature of this new transformation involving no metal alkynides can be visualized by the fact that the alkynyl group bearing keto carbonyl was transferred successfully to aldehyde carbonyl without any side reactions on keto carbonyl. Although the use of (S)-1,1[prime or minute]-bi-2-naphthol and its simple analogues was found to be unsuitable for inducing asymmetry in this reaction, design of new chiral biphenols bearing a certain flexibility of the biphenyl axis led to satisfactory results in terms of enantioselectivity as well as reactivity.