Synthesis of nonracemic allylic hydroxy phosphonates via alkene cross metathesis
Synthesis of nonracemic allylic hydroxy phosphonates via alkene cross metathesis
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DOI：
10.1021/jo0490090
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发表时间：
2004-12-10
影响因子：
3.6
通讯作者：
Rath, NP
中科院分区：
文献类型：
--
作者：
He, AY;Yan, BL;Rath, NP
烯丙基羟基膦酸酯及其衍生物可以通过使用第二代格鲁布斯催化剂的交叉复分解进行相互转化。起始膦酸酯的绝对立体化学在产物中是保守的。丙烯醛衍生的膦酸酯 2a 的交叉复分解反应产生一系列官能化的烯丙基羟基膦酸酯。然而，交叉复分解反应常常伴随着竞争性二聚和烯烃迁移反应，导致产率降低。还检测了肉桂醛和巴豆醛衍生的膦酸酯 2b 和 2C。一般来说，膦酸酯 2b 和 2c 的复分解反应比膦酸酯 2a 的复分解反应慢得多，从而形成混合物。膦酸酯 2a 的几种羟基保护衍生物（碳酸甲酯 3a、乙酸酯 4a、N-甲苯磺酰基氨基甲酸酯 5a、TBDMS 6a 和乙酰乙酸酯 7a）可进行复分解，而不会发生竞争性副反应，以良好至优异的产率生成取代的烯丙基膦酸酯。
Allylic hydroxy phosphonates and their derivatives can be interconverted by using cross metathesis with second generation Grubbs catalyst. The absolute stereochemistry of the starting phosphonate is conserved in the product. Cross metathesis reaction of the acrolein-derived phosphonate 2a yields a series of functionalized allylic hydroxy phosphonates. However, the cross metathesis reaction is often accompanied by competing dimerization and alkene migration reactions leading to a reduction in yield. The cinnamaldehyde- and crotonaldehyde-derived phosphonates 2b and 2C were also examined. In general, the metathesis reactions of phosphonates 2b and 2c are considerably slower than those for phosphonate 2a leading to mixtures. Several hydroxyl-protected derivatives of the phosphonate 2a (methyl carbonate 3a, acetate 4a, N-tosyl carbamate 5a, TBDMS 6a, and acetoacetate 7a) undergo metathesis without competing side reactions to give substituted allylic phosphonates in good to excellent yield.