He Anyu, Yan Bingli, Thanavaro Anchalee, Spilling Christopher D, Rath Nigam P
Department of Chemistry and Biochemistry, University of Missouri-St. Louis, 8001 Natural Bridge Road, St. Louis, MO 63121, USA.
J Org Chem. 2004 Dec 10;69(25):8643-51. doi: 10.1021/jo0490090.
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.
烯丙基羟基膦酸酯及其衍生物可通过与第二代格拉布催化剂进行交叉复分解反应实现相互转化。起始膦酸酯的绝对立体化学在产物中得以保留。源自丙烯醛的膦酸酯2a的交叉复分解反应生成了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的二聚反应和烯烃迁移反应，导致产率降低。还对源自肉桂醛和巴豆醛的膦酸酯2b和2c进行了研究。一般来说，膦酸酯2b和2c的复分解反应比膦酸酯2a的反应要慢得多，会生成混合物。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、叔丁基二甲基硅烷基醚6a和乙酰乙酸酯7a）进行复分解反应时没有竞争性副反应，能以良好到优异的产率得到取代的烯丙基膦酸酯。
