Study Concerning the Effects of Chelation on the Structure and Catalytic Activity of Ruthenium Carbene Complexes
摘要:
The ruthenium chelate complexes 4 and 5 were prepared by reaction of the Grubbs catalyst 1 and its second-generation analogue 2 with the 2-vinylbenzoic acid isopropyl ester 3 in the presence of CuCl. The fact that the chelating carbonyl group in these complexes attenuates their catalytic activity sets an experimental basis for the interpretation of reactivity data previously described in the literature.
Improved One-Pot Synthesis of Second-Generation Ruthenium Olefin Metathesis Catalysts
摘要:
An improved one-pot synthesis of olefin metathesis catalysts (PCy3)(L)Ru=CHPhCl2 (L = N-heterocyclic nueleophilic carbene: IMes, 3; SIMes, 4) employs potassium tert-amylate to deprotonate the imidazolium salt ligand precursor. Both of the reaction steps are carried out using a one-pot protocol in hexane with commercially available reagents under mild conditions, permitting the isolation of 3 and 4 by simple filtration.
Domino Metathesis of 2-Azanorbornenones: A New Strategy for the Enatioselective Synthesis of 1-Azabicyclic Compounds
摘要:
Domino metathesis of N-alkylated derivatives of (1S)-2-azanorborn-5-en-3-one allowed for the enantioselective synthesis of pyrrolizidine, quinolizidine, pyrrolidinoazepine, and pyrrolidinoazocine derivatives in a straightforward process.