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Wed, 01 Mar 2023
Events, Seminar Series
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Dr. Johanna Blaquiere

Western University

Harnessing Ligand Dynamics for Productive Catalysis

Wednesday, March 01, 2023
ASB10900 @ 3:30 p.m.

Host: Dr. Caterina Ramogida

 

Abstract

Responsive changes in ligand coordination mode occur for a wide range of ligand structures, and these dynamics can promote organometallic reactions, such as substitution, oxidative addition/reductive elimination, and insertion/elimination.[1] Hemilabile ligands are a common subset of these structurally-responsive ligands, in which reactivity is promoted by changes in ligand chelation. Alternatively, reactivity promoted by dynamic coordination changes of π-bound ligands are less common. We have designed a phosphine 1-azaallyl (P^AzA) ligand that exhibits a variety of coordination modes in response to the demands of the metal centre. The P^AzA ligand effectively stabilizes an operationally-unsaturated ruthenium complex (1), a type of structure that is common of active catalysts.[2] A dimeric Pd P^AzA methyl complex (2), undergoes dinuclear reductive elimination to give ethane and a Pd(I) dimer (3) as products.[3] Experimental and computational mechanistic analysis reveals that the capacity of the 1-azaallyl group to bridge two metals through a variety of coordination modes promotes bimetallic reductive elimination pathways.[4] We have exploited this unusual dinuclear reductive elimination for catalytic C-C bond formation.

References

[1] J.M. Blacquiere, ACS Catal. 2021, 11, 5416-5437.
[2] M.B. Kindervater, K.M.K. Jackman, A.A. Fogh, V.N. Staroverov, L. Lim, S.A. Sirohey, P.D. Boyle, J.M. Blacquiere, Submitted
[3] K.M.K. Jackman, B.J. Bridge, E.R. Sauvé, C.N. Rowley, C.H.M. Zheng, J.M. Stubbs, P.D. Boyle, J.M. Blacquiere, Organometallics 2019, 38, 1677-1681.
[4] K.M.K. Jackman, G. Liang, P.D. Boyle, P.M. Zimmerman, J.M. Blacquiere, Dalton Trans. 2022, 51, 3977

Research Interests

The Blacquiere group is targeting fundamental studies of transition-metal complexes for applications in sustainable catalysis. Current demands in the fine chemicals industry for the construction of high-value compounds by streamlined, low- toxicity and low-waste approaches is driving the need for new synthetic methods. This research program will target selective functionalization strategies that activate abundant small molecules such as H2O and O2. Ultimately first-row metal complexes will be employed, where design strategies, in some cases, will be informed by more tractable second-row analogues.