Isopentenyl and dimethylallyl acetates and cinnamates have been found in large amounts in an essential oil obtained from the ripe fruit of Pandanus tectorius, their identification has been confirmed by synthesis. This is the first time that these esters, apart from one, have been found in the plant kingdom and, generally speaking, that monoterpene precursors predominate in an essential oil. Copyright (C) 1996 Published by Elsevier Science Ltd
A simple, mild and efficient procedure for selective cleavage of prenyl esters using silica-supported sodium hydrogen sulphate as a heterogenous catalyst
作者:C Ramesh、G Mahender、N Ravindranath、Biswanath Das
DOI:10.1016/s0040-4039(02)02858-7
日期:2003.2
Prenyl esters were selectively and efficiently cleaved under slightly acidic reaction conditions using silica-supported sodium hydrogen sulfate as a heterogenous catalyst at room temperature to regenerate the parent carboxylic acids in very high yields.
Dirhodium(II)-Mediated Alkene Epoxidation with Iodine(III) Oxidants
作者:Ali Nasrallah、Gwendal Grelier、Maria Ivana Lapuh、Fernando J. Duran、Benjamin Darses、Philippe Dauban
DOI:10.1002/ejoc.201800306
日期:2018.11.15
combination of the dirhodium(II) complex Rh2(tpa)4 (tpa = triphenylacetate) with the iodine(III) oxidant PhI(OPiv)2 is shown to promote the epoxidation of alkenes in the presence of 2 equivalents of water. The reaction can be applied to diversely substituted alkenes and the corresponding epoxides are isolated with yields of up to 90 %. A possible mechanism involves the dirhodium(II) complex as a Lewis
Dirhodium (II) 络合物和碘 (III) 氧化剂已在合成氮烯化学中找到有用的应用。在这项研究中,二铑(II)配合物 Rh2(tpa)4(tpa = 三苯乙酸盐)与碘(III)氧化剂 PhI(OPiv)2 的组合被证明在 2 当量的水。该反应可应用于不同取代的烯烃,并以高达 90% 的产率分离相应的环氧化物。一种可能的机制涉及二铑 (II) 络合物作为路易斯酸物质,它可以调节碘 (III) 试剂的氧化特性。