Two syntheses of macrolides olefin methathesis are presented. The first (A) involves preparation of ω-hydroxyacid or by metathesis followed by cyclisation, while the second (B) involves macrocyclic ring closure by metathesis of a ω,ω′diunsaturated ester .
Mesocellular Foam-Supported Catalysts: Enhanced Activity and Recyclability for Ring-Closing Metathesis
作者:Jaehong Lim、Su Seong Lee、Siti Nurhanna Riduan、Jackie Y. Ying
DOI:10.1002/adsc.200600442
日期:2007.5.7
siliceous mesocellular foam (MCF). The open and interconnected pores of MCF facilitated ligand immobilization and substrate diffusion. We have observed that the ligand and metal loadings significantly affected the catalytic activity and recyclability. Enhancedrecyclability by suppression of ruthenium leaching was achieved by using excess immobilized ligands. The resulting novel heterogenized catalysts demonstrated
[EN] A HIGHLY EFFICIENT SYNTHESIS OF Z-MACROCYCLES USING STEREORETENTIVE, RUTHENIUM-BASED METATHESIS CATALYSTS<br/>[FR] SYNTHÈSE HAUTEMENT EFFICACE DE MACROCYCLES Z À L'AIDE DE CATALYSEURS DE MÉTATHÈSE À BASE DE RUTHÉNIUM STÉRÉORÉTENTIFS
申请人:CALIFORNIA INST OF TECHN
公开号:WO2018208501A1
公开(公告)日:2018-11-15
A highly efficient, Z-selective ring-closing metathesis system for the formation of macrocycles using a stereoretentive, ruthenium-based catalyst supported by a dithiolate ligand is reported. This catalyst is demonstrated to be remarkably active as observed in initiation experiments showing complete catalyst initiation at - 20°C within 10 min. Using easily accessible diene starting materials bearing a Z-olefin moiety, macrocyclization reactions generated products with significantly higher Z-selectivity in appreciably shorter reaction times, in higher yield, and with much lower catalyst loadings than in previously reported systems. Macrocyclic lactones ranging in size from twelve-mem bered to seventeen-membered rings are synthesized in moderate to high yields (68 - 79% yield) with excellent Z-selectivity (95% - 99% Z).
Thirteen‐ to eighteen‐membered lactones were synthesized by ring‐closing olefin‐metathesis reactions of bis‐olefins with heterogeneous Grubbs‐supported ionic‐liquid catalysts (SILCs), in which homogeneous Grubbs catalysts were confined in pores of alumina with the aid of an ionic liquid. The Grubbs‐SILCs exhibited higher catalyticperformance than their homogeneous counterparts and could be repeatedly
The present invention relates to a method for producing metathesis products comprising contacting metathesis starting materials under metathesis conditions with a metathesis catalyst, wherein the metathesis catalyst is employed in an amount of from 0.0001 mol-% to 1 mol-% based on half of the sum of the reactive double bonds of the metathesis starting materials and wherein the ethylene or propylene generated in the course of the reaction is removed from the reaction mixture.