931092-90-9Relevant academic research and scientific papers
Impact of electronic modification of the chelating benzylidene ligand in cis-dichloro-configured second-generation olefin metathesis catalysts on their activity
Pump, Eva,Poater, Albert,Zirngast, Michaela,Torvisco, Ana,Fischer, Roland,Cavallo, Luigi,Slugovc, Christian
supporting information, p. 2806 - 2813 (2014/06/24)
A series of electronically modified second-generation cis-dichloro ruthenium ester chelating benzylidene complexes was prepared, characterized, and benchmarked in a typical ring-opening metathesis polymerization (ROMP) experiment. The electronic tuning of the parent chelating benzylidene ligand (2-ethyl ester benzylidene) was achieved by substitution at the 4- and 5-positions with electron-withdrawing nitro or electron-donating methoxy groups. The effect of the electronic tuning on the cis-trans isomerization process was studied experimentally and theoretically. Density functional theory calculations clearly revealed the influence of electronic modification on the relative stability between the cis and trans isomers, which is decisive for the activity of the studied compounds as initiators in ROMP.
Synthesis of macrolide-saccharide hybrids by ring-closing metathesis of precursors derived from glycitols and benzoic acids
Matos, Marie-Christine,Murphy, Paul V.
, p. 1803 - 1806 (2007/10/03)
The benzomacrolactone structural motif is a privileged or evolutionarily selected scaffold that codes properties required for binding to proteins and novel analogues thereof may provide a source of new bioactive compounds. Saccharides are also privileged structures, with (amino)sugars, imino-sugars, and sugar amino acids being applied as scaffolds for the development of nonpeptidal peptidomimetics. The syntheses of novel polyhydroxylated oxamacrolides, structural analogues of natural polyketide derived macrolides, are described herein, providing a basis for their development as scaffolds. The syntheses were carried out from benzoic acids and appropriately protected D-mannitol or D-sorbitol (D-glucitol). Ring-closing metathesis was applied in the macrocyclization step with high E-alkene selectivities being observed. X-ray crystal structures, for two polyhydroxylated derivatives, show that the macrocyclic rings display similar conformations. In addition, intermolecular hydrogen-bonding networks are observed in the lattices.
