Some rearrangements of unsaturated phosphonate esters
作者:Dianne Cooper、Stuart Trippett
DOI:10.1039/p19810002127
日期:——
α-Hydroxyalk-2-enylphosphonates undergo Claisen orthoester rearrangement on heating with orthoesters, and their arylsulphenates undergo [2,3]-sigmatropic rearrangement to give 3-arylsulphinylalk-1-enylphosphonates. The addition of allyloxide anion to the central carbon of the allene Me2CCCHP(O)(OEt)2 is followed by rapid Claisen rearrangement of the resulting allylic carbanion to give the two possible
与原酸酯一起加热时,α-羟基烷-2-烯基膦酸酯会发生Claisen原酸酯重排,其芳基磺酸酯会发生[2,3]-σ重排,从而生成3-芳基亚磺酰基烷基-1-烯基膦酸酯。在烯丙基Me 2 C C CHP(O)(OEt)2的中心碳上添加烯丙氧基阴离子后,对所得的烯丙基碳负离子进行快速克莱森重排,得到两种可能的β-酮烷基膦酸酯。已制备出通式为R 1 R 2 C CH [CH 2 ] n CR 3 C CHP(O)(OEt)2的烯丙基膦酸酯:当R 1 = R 2时= H,R 3= Me,且n= 2,发生对映体重排以得到异构二烯;α= H,R 3= Me,n= 2。当R 1,R 2,R 3= Me且n= 0时,[1,5]氢化物转移得到三烯,然后环化成环己二烯;当R 1 = Me,R 2 = H,R 3 = H或Me且n = 0时,二烯组分可用于Diels–Alder反应。
Mechanistic approach for expeditious and solvent-free synthesis of α-hydroxy phosphonates using potassium phosphate as catalyst
作者:Makarand A. Kulkarni、Uday P. Lad、Uday V. Desai、Satish D. Mitragotri、Prakash P. Wadgaonkar
DOI:10.1016/j.crci.2012.10.009
日期:2013.2
Résumé An extremely simple, high yielding, highly rapid and solvent-free protocol has been described for hydrophosphylation of aldehydes using potassium phosphate as catalyst. Easy commercial availability of the reusable catalyst, operational simplicity at ambient temperature and avoidance of conventional work-up as well as purification procedure makes this solvent-free protocol a near-ideal synthesis. Supplementary Materials: Supplementary material for this article is supplied as a separate file: mmc1.pdf
A novel organocatalytic, direct synthesis of α-hydroxyphosphonates via reaction of aldehydes and ketones with trimethylphosphite in the presence of catalytic amounts of pyridine 2,6-dicarboxylic acid in water is reported. The method is simple, cost-effective and environmentally benign. α-hydroxyphosphonates - organocatalyst - pyridine 2,6-dicarboxylic acid - nucleophilic addition - water
An efficient and simple synthesis of α‐hydroxyphosphonates via reaction of aldehydes and ketones with dimethylphosphite in the presence of MgCl2/Et3N base system is reported. The use of readily available and easy to handle reagent MgCl2/Et3N makes this method simple, convenient, and practical.
据报道,在MgCl 2 / Et 3 N碱体系存在下,醛和酮与亚磷酸二甲酯反应可有效,简单地合成α-羟基膦酸酯。使用易于获得且易于处理的试剂MgCl 2 / Et 3 N使该方法简单,方便且实用。
A Convenient Synthesis of Dialkyl 1-Hydroxyalkanephosphonates using Potassium or Caesium Fluoride without Solvent