A Selective and Functional Group-Tolerant Ruthenium-Catalyzed Olefin Metathesis/Transfer Hydrogenation Tandem Sequence Using Formic Acid as Hydrogen Source
作者:Grzegorz K. Zieliński、Jarosława Majtczak、Maciej Gutowski、Karol Grela
DOI:10.1021/acs.joc.7b02468
日期:2018.3.2
A ruthenium-catalyzed transferhydrogenation of olefins utilizing formic acid as a hydrogen donor is described. The application of commercially available alkylidene ruthenium complexes opens access to attractive C(sp3)-C(sp3) bond formation in an olefin metathesis/transferhydrogenation sequence under tandem catalysis conditions. High chemoselectivity of the developed methodology provides a remarkable
New robust and air-stable ruthenium(II) indenylidene type second-generation precatalysts with unsymmetrical N-heterocycliccarbene (NHC) ligands were synthesized. The reaction profiles of these complexes were studied in commercial-grade solvents in air with model substrates leading to the di-, tri-, and tetrasubstituted olefins. In addition, application of selected precatalysts for olefin metathesis
Thermal Switchability of N-Chelating Hoveyda-type Catalyst Containing a Secondary Amine Ligand
作者:Karolina Żukowska、Anna Szadkowska、Aleksandra E. Pazio、Krzysztof Woźniak、Karol Grela
DOI:10.1021/om2011062
日期:2012.1.9
An investigation of aza analogues of the popular Hoveyda–Grubbs catalystcontaining a secondaryamineligand is presented, proving the crucial impact of steric as well as electronic factors on the catalyst’s stability and performance. The issue of latency in the reactivity profile of studied catalysts is examined, followed by structural and application studies.
A low-waste, time-economical, and scalable semiheterogeneous purification protocol for the removal of ruthenium residues from olefinmetathesis (OM) reactions has been developed. It is based on the non-covalent immobilization of the commercially available isocyanide 1,4-bis(3-isocyanopropyl)piperazine (QA) on unmodified silica gel. The use of the heterogeneous scavenger [email protected]2 synthesized
Five Hoveyda–Grubbs‐type complexes bearing cyclopropyl to cycloheptyl ether moieties in the chelating benzylideneligand have been synthesized and investigated by spectroscopic and crystallographic methods. Their experimentally measured catalytic activity in model ring‐closing metathesis (RCM) reactions was studied at catalyst loading down to 10 ppm and compared with DFT calculations. The latter can