Conformationally Unbiased Macrocyclization Reactions by Ring Closing Metathesis

Abstract

General. All reactions were carried out under Ar using Schlenk techniques. Chemical shifts are listed downfield in ppm relative to tetramethylsilane. Coupling

Katalyse und Totalsynthese: eine persönliche Zwischenbilanz

“…[76,77] Das dadurch ausgelçste lawinenartige Interesse an der Metathese hat die Art, wie organische Chemie jetzt und in Zukunft betrieben wird, nachhaltig verändert. [78][79][80][81][82] Vielleicht haben einige unserer frühen Beiträge, besonders zur Synthese mittlerer [11,12] und großer Ringe [83][84][85] durch Ringschluss-Olefinmetathese (RCM, ring-closing metathesis), ein wenig mitgeholfen, diese Methode nicht nur populär zu machen, sondern auch ihre in mancher Hinsicht zur klassischen Synthese komplementäre Logik zu verdeutlichen. [86] Dieser Aspekt zeigt sich zum Beispiel an unseren Zugängen zu diversen Glycolipiden wie Tricolorin, Woodrosin, den Ipomoeassinen oder der vermuteten Struktur von Gobienin A.…”

Ruthenium‐Catalyzed Ring‐Closing Metathesis: Recent Advances, Limitations and Opportunities

“…RCM of 1 using C1a and related catalysts is reportedly incomplete even after 30 h [151][152][153][154], while NHC catalyst C2b effects 72-87% ring-closing within 2-4 h [80,151]. In comparison, C51b effects quantitative formation of this value-added target molecule within 15 minutes [65].…”

Catalytic Performance of Ruthenium‐Supported Ionic‐Liquid Catalysts in Sustainable Synthesis of Macrocyclic Lactones

“…Although this compound has been previously synthesized by olefin metathesis employing heterogeneous [7] as well as homogeneous Grubbs catalysts [21], to the best of our knowledge, there is no precedent for recycling the catalyst, particularly in the reaction of inexpensive allyl eruciate (16). The metathesis reaction of 16 catalyzed by Gr1-SILC 8 afforded the desired sixteen-membered lactone 23 when carried out in refluxing benzene to prevent rapid thermal decomposition of the catalyst.…”