Research

  1. Alkylidene Complexes; Synthesis and Mechanisms

This research involves the synthesis of new high oxidation state early metal complexes that contain an alkylidene ligand. Since 2007 the majority of investigations involve new monoalkoxide pyrrolide (MAP) complexes in which the metal is a stereogenic center. MAP catalysts offer many practical advantages over previous bisalkoxide or diolate catalysts, and also allow several fundamental mechanistic issues to be addressed for the first time. Monoalkoxide halide (MAX) complexes have opened a new chapter in metathesis chemistry of difficult substrates, especially electron poor olefins such a dihaloethylenes.  A detailed description (doc file) can be found here.

2. Olefin Metathesis in Organic Chemistry

This research involves the application of metathesis reactions in organic chemistry. Most recently the research has focussed on reactions that produce as high as >99% Z products in good yields. Examples include Z-selective coupling of terminal olefins, ethenolysis, cross-metathesis, ring-closing, or alkane metathesis reactions. Applications are focussed on the synthesis of natural products. A recent advance has been the stereoselective (Z) cross metathesis of ordinary olefins with electron poor olefins such as Z 1,2-dichloroethylene or Z-1,1,1,4,4,4-hexafluoroethylene.  A detailed description (doc file) can be found here.

3. Olefin Metathesis in Polymer Chemistry

This research involves the application of new alkylidene complexes to the stereoselective ring-opening metathesis polymerization (ROMP) reactions. We are especially interested in the synthesis of polymers that have a single structure and how that structure is related to the polymer's properties. Recent discoveries include the synthesis of alternating AB copolymers where A and B are enantiomers.  A detailed description (doc file) can be found here.