Organic Seminar: Beyond Total Synthesis: An Unplanned Journey into Organo-Bismuth Chemistry

The synthesis of complex natural products often provides opportunities for the discovery of new reactions and concepts that find application well beyond the original synthetic objective. Such was our experience during studies directed toward the ambiguine alkaloids, a structurally intricate subgroup of the hapalindole family of natural products. While these efforts culminated in concise syntheses of several ambiguines, they also revealed the need for a more efficient preparation of a key synthetic intermediate.

Robert W. Taft Memorial Lecture: Chemoselective, Site-Selective, and Catalytically Controlled Tetrazine Ligations

As the fastest bioorthogonal reaction, tetrazine ligation is widely utilized across chemical biology, medicine, nuclear medicine, and materials science. This talk will present the development of thioalkyltetrazines as multipurpose functional groups that serve both as practical synthetic building blocks for traditional tetrazine reagents and as chemo- and site-selective probes for protein modification, protein–protein conjugation, and cellular profiling.

Inorganic Seminar: mm-Wave pulse EPR spectroscopy of high spin transition metal centers

Electron Paramagnetic Resonance (EPR) is most often performed in microwave frequency bands, with X-band (~9.4 GHz) being the most common. With superconducting magnets, one can explore higher frequency EPR spectroscopy.   This has mostly been done at low rf power due to difficulties in obtaining high rf power levels as one approaches mm-wave frequencies.  There has been a good bit of low power continuous wave (CW) EPR at higher frequencies, but the lack of high power and high bandwidth pulse amplifiers has limited pulse EPR instrumentation.