New concepts for the synthesis and reactivity of sulfur ylides

硫叶立德是有机化学中的经典教材试剂，占有非常重要的地位。最近，我们开发了一个可靠的概念，通过一步叶立德转移直接合成硫叶立德，并以高效率进行。我们还发现了一种新型的硫叶立德对金催化剂的反应活性，使多取代呋喃和含季中心的呋喃酮的合成成为可能。在此，我们提出了一系列新的方法，用于在温和的条件下催化硫叶立德的转化。将开发一种创新的电子中性烯烃环丙烷化反应，它有可能进行高水平的不对称诱导，并将提供一种有吸引力的替代目前涉及爆炸性和危险重氮化合物的最先进方法。改进的用于叶立德转移的化学物质将使这些过程可持续和廉价。此外，机理和理论研究应对这些反应的细节提供关键的见解。最后，将研究在这一领域的初步研究过程中遇到的前所未有的烯丙基酯的烯丙基异构化。

Sulfur ylides occupy a very important place as classical textbook reagents in organic chemistry. Recently, we have developed a robust concept for the direct synthesis of sulfonium ylides by a one-step ylide transfer that proceeds in high levels of efficiency. We have also discovered a novel reactivity manifold of sulfonium ylides towards gold catalysts that enables a versatile synthesis of polysubstituted furans and furanones bearing quaternary centers.Herein, we propose an extended array of new methodologies for catalytic transformations of sulfur ylides under mild conditions. An innovative cyclopropanation of electron-neutral olefins, that has the potential to proceed with high levels of asymmetric induction and which shall offeran attractive alternative to current state-of-the-art methods involving explosive and hazardous diazo compounds, will be developed. Improved chemistry for ylide transfer shall render those processes sustainable and cheap. In addition, mechanistic and theoretical studies shall provide key insight on the details of these reactions. Finally, an unprecedented allylic isomerisation of allylic esters, encountered in the course of preliminary studies in this field, willbe studied.