Organometallic Synthesis and Mechanisms

The Grubbs Group examines the fundamental organometallic chemistry required for the design and synthesis of catalysts for use in organic and polymer synthesis. Catalysts for olefin metathesis have been the focus of the research over the past several years. As a result, a family of ruthenium catalysts have been developed that have opened the door to a wide variety of applications for olefin metathesis. The tolerance of these complexes to functional groups and their ease of use have been the keys to their broad use. Underlying the development and improvement in these catalysts has been a detailed understanding of their mechanism of reaction. Continuing efforts are being made to further improve and broaden the use of these catalysts. These ongoing studies involve ligand and new transition metal complex synthesis as well as continuing examination of the mechanistic features that control the activity and selectivity of these catalysts. Recently, the Division has created the Center for Catalysis and Synthesis, which our group uses for the rapid screening of new catalyst systems.

Selected Recent Publications

High Trans Kinetic Selectivity in Ruthenium-Based Olefin Cross-Metathesis through Stereoretention
Johns, A. M.; Ahmed, T. S.; Jackson, B. W.; Grubbs, R. H.; Pederson, R. L.
Org. Lett. 2016, 18, 772-775.

Probing Stereoselectivity in Ring-Opening Metathesis Polymerization Mediated by Cyclometalated Ruthenium-Based Catalysts: A Combined Experimental and Computational Study
Rosebrugh, L. E.; Ahmed, T. S.; Marx, V. M.; Hartung, J.; Liu, P.; López, J. G.; Houk, K. N.; Grubbs, R. H.
J. Am. Chem. Soc. 2016, 138, 1394-1405.

Z-Selectivity in Olefin Metathesis with Chelated Ru Catalysts: Computational Studies of Mechanism and Selectivity
Liu, P.; Xu, X.; Dong, X.; Keitz, B. K.; Herbert, M. B.; Grubbs, R. H.; H., K. N.
J. Am. Chem. Soc. 2012, 134, 1464-1467.

Chelated Ruthenium Catalysts for Z-Selective Olefin Metathesis
Endo, K.; Grubbs, R. H.
J. Am. Chem. Soc. 2011133, 8525-8527.

Organic Synthesis

Over the past several years, a number of olefin metathesis-based transformations have become important in organic synthesis, as the functional group tolerance of ruthenium-based catalysts allows for the preparation of complex molecules without the use of protecting groups. The most broadly used method is ring-closing metathesis (RCM) to form a variety of cyclic olefins. Five- to over 82-membered rings have been prepared in good yield using olefin metathesis. Additionally, definition of the rules governing cross metathesis has opened its application to the synthesis of a variety of functional molecules. The focus of the group at this time is on the synthesis of more active and selective systems. Catalysts that provide high enantioselectivity in RCM and high stereoselectivity in cross metathesis are being developed. Other metal-catalyzed reactions including oxidations and tandem metathesis/oxidation are also areas of study.

Selected Recent Publications

Tandem Z-Selective Cross-Metathesis/Dihydroxylation: Synthesis of anti-1,2-Diols
Dornan, P. K.; Wickens, Z. K.; Grubbs, R. H.
Angew. Chem., Int. Ed. 2015, 54, 7134-7138.

Enantioselective Olefin Metathesis with Cyclometalated Ruthenium Complexes
Hartung, J.; Dornan, P. K.; Grubbs, R. H.
J. Am. Chem. Soc. 2014, 136, 13029-13037.

Catalyst-Controlled Wacker-Type Oxidation: Facile Access to Functionalized Aldehydes
Wickens, Z. K.; Skakuj, K.; Morandi, B.; Grubbs, R. H.
J. Am. Chem. Soc. 2014, 136, 890-893.

Polymer Synthesis

Ring-opening metathesis polymerization (ROMP) allows for the synthesis of highly functionalized polymers with controlled structures. By tuning of the structure of ruthenium-based metathesis catalysts, the opportunities afforded by ROMP have been greatly expanded. Recent methods have been developed that are being used to prepare cyclic olefins, alternating copolymers, and multiblock copolymers with a broad array of functionality. The properties and applications of these new materials are currently being explored.

Selected Recent Publications

ABA Triblock Brush Polymers: Synthesis, Self-Assembly, Conductivity, and Rheological Properties
Bates, C. M.; Chang, A. B.; Momćilović, N.; Jones, S. C.; Grubbs, R. H.
Macromolecules 2015, 48, 4967-4973.

Rapid Self-Assembly of Brush Block Copolymers to Photonic Crystals
Sveinbjörnsson, B. R.; Weitekamp, R. A.; Miyake, G. M.; Xia, Y.; Atwater, H. A.; Grubbs, R. H.
Proc. Natl. Acad. Sci. U.S.A. 2012, 109, 14332-14336.

Efficient Synthesis of Narrowly Dispersed Brush Copolymers and Study of Their Assemblies: The Importance of Side Chain Arrangement
Xia, Y.; Olsen, B. D.; Kornfield, J. A.; Grubbs, R. H.
J. Am. Chem. Soc. 2009, 131, 18525-18532.