Professor Ian Tonks

CSENG Chemistry
College of Science & Engineering
Twin Cities
Project Title: 
Ti Redox Catalysis and Alkene Hydroesterification

These researchers are working on two projects using MSI resources:

  • Early Metal Redox Catalysis and Reaction Development:

The long-term goal of this research program is to design new early transition metal-catalyzed reactions for the synthesis of complex molecular architectures from simple precursors. The rationale for using early transition metals (TMs) is that they are earth abundant and generally nontoxic: important factors in the design of sustainable, efficient, and practical synthetic methods. There have been significant recent advances in the utilization of earth abundant late TMs such as Fe, Co, Ni, and Cu in catalysis, but early TMs such as Ti have largely been left behind despite being more abundant and benign than the late TM analogues.

A significant challenge of working with early TMs is that they typically do not undergo facile oxidation state changes due to the thermodynamic stability of their highest oxidation states. In contrast, many late TM-catalyzed reactions require 1- or 2- electron redox changes at the metal center, such as oxidative addition or reductive elimination reactions. As a result, early TM-catalyzed synthetic methods have typically been limited to simple Lewis acid or hydrofunctionalization/insertion-type reactions. This limitation is largely borne out of a general lack of reaction development rather than an inherent lack of utility, and our current and future research program is focused on exploiting this disparity and bringing earth-abundant, inexpensive, and nontoxic Ti redox catalysis into the realm of modern synthetic methodology.

  • Catalytic Alkene Hydroesterification for Polyester Synthesis:

This group has a separate interest in designing new catalytic routes to new advanced polyolefin materials, with a specific emphasis on oxygenated polyolefins such as polyketones, polyesters, and polyketoesters. These types of oxygenated polyolefins are important materials due to their potential biodegradability, paintability, and high Tm values. The researchers propose that a common catalytic intermediate - a metal acyl - should make it possible to connect two distinct catalytic reactions, olefin/CO copolymerization and olefin hydroesterification, into a single process. By combining these reactions, it will be possible to couple inexpensive, biorenewable a,w-enols into olefin/CO co-polymerizations, giving access to broad new classes of polyesters and polyketoesters. In order to build a rational base for innovating and improving hydroesterificative polymerizations, researchers need to improve their understanding of the fundamental theory and application of alkene hydroesterification, including how catalyst structure impacts the selectivity of hydroesterification vs. polyketone formation. This group will carry out a detailed multivariate study of hydroesterification in order to build better quantitative and predictive models for ligand and reaction design. An in-depth theoretical understanding of hydro-esterification will have industrial applications, as well as significant opportunities for applying hydroesterification in other arenas as well, ranging from fine chemical to commodity synthesis.

 

Project Investigators

Steven Butler
Rachel Dunscomb
Connor Frye
Robin Harkins
Michael Harris
Jaekwan Kim
Shao-Yu Lo
Kate Rynders
Janaya Sachs
Professor Ian Tonks
 
Are you a member of this group? Log in to see more information.