CCB Departmental Seminar – Prof. Johanna M. Blacquiere, Department of Chemistry, Western University
Mar 11, 2021
1:30PM to 2:30PM
Date(s) - 11/03/2021
1:30 pm - 2:30 pm
Title: Proton- and Structurally-Responsive Ligands for Catalysis
Date: Thursday, March 11th, 2021
Time: 1:30 p.m.
Zoom: available from firstname.lastname@example.org
Host: Dr. David Emslie
The capacity for ligand structure toinduce unique reactivity is a guiding principle in the field of transitionmetal catalyst design. Beyond stereo-electronic tuning of the metal,cooperative ligands induce reversible changes in the catalyst structure toachieve catalytic turnover. Two cooperative ligand types that we areinvestigating include: proton- responsive ligands that mediate H+ transferor H-bonding interactions, and structurally- responsive ligands that modulatemetal reactivity by changes in ligand coordination mode. Both of these ligandtypes will be covered in this seminar. First, we have demonstrated that[M(Cp/Cp*)(PR2NR’2)(MeCN)]PF6 catalysts(1), where M = Ru, Fe, are active catalysts for the intramolecularhydroamination and hydroalkoxylation of alkynes to selectively afford endo (ratherthan exo) heterocycles. The PR2NR’2 ligand functions to shuttleprotons during the catalytic cycle, which avoids the need for exogenous basesas additives. Performance assessment of catalyst derivatives and mechanisticstudies have revealed optimal structural features to achieve high catalyst performance.The second portion of the presentation will cover the role of astructurally-responsive ligand to enable an unusual Csp3-Csp3 bondformation from 2. The ligand structure contains a1-azaallyl moiety that displays versatile coordination chemistry to support avariety of structures, including bimetallic and monometallic complexes withpalladium in a +2 and +1 oxidation state.
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