Reports: SE
49664-SE Modern Acetylene Chemistry, at the 92nd Canadian Society for Chemistry National Meeting, May 30-June 3, 2009, Hamilton, ON
The symposium was ultimately scheduled for the morning of last day of the conference, and attendance was somewhat less than had been expected. Nevertheless, there was a solid nucleus of attendees throughout the session who drove discussion following each of the talks. In fact, participation of the lecture attendees through comments, questions, and discussion was truly one of the highlights. For nearly every talk, time did not allow for addressing all questions, which is quite unusual for general conferences such as this. Given that the Canadian Chemistry community is quite small, I recognized many of the faces in crowd, and it was typically composed of ca. 50% graduate students, 25% academic faculty, 25% PDFs.
The first talk of the day was Dr. Khalid Azyat (University of Alberta), a contributed talk that addressed the formation of series of alkyl tethered polycyclic aromatic hydrocarbons designed to mimic the complex aggregation behavior of asphaltenes present in the Athabasca oil sands. A great introduction to the origin and nature of asphaltenes provided for a talk that I am sure was of interest to everyone in the room. Estimated attendance: 12 (initial)-20 (final).
The second talk was presented by Prof Yuming Zhao (Memorial University of Newfoundland). Dr. Zhao is a young researcher in Canada, but one who is already making an impact through work with pi-extended tetrathiafulvalenes. His talk nicely wove together the synthesis of these conjugated acetylenic scaffolds with the characterization of electronic attributes toward optimizing, for example, properties necessary for optoelectronic applications such as solar cells. In addition, a recent achievement from this group provides the basis for the possible realization of redox active molecular sensors. Estimated attendance: 20-30.
The next talk was from Prof CJ Li (McGill University) who is recognized nationally and internationally as a leader in catalytic reactions involving the addition of acetylenes to various electrophiles. What makes this work particularly important are his achievements in the area of green chemistry. Nearly all of the transformations describe by Li are done in water, often with very low catalyst loading. Furthermore, many of the protocols are also multicomponent reactions, where the reaction of at least three precursors is orchestrated in a single synthetic step. Estimated attendance: 30-40.
Prof Martin Bryce (Durham University) was the fourth speaker of the day (he was one of the speakers supported by the PRF Grant), describing his work toward donor-acceptor acetylenic molecules suitable for energy transfer systems. A particularly interesting aspect of this work is his discovery that many terminal di, tri and even tetraynes can be isolated as stable solids for subsequent elaboration through various cross-coupling protocols. His work has basically dispelled the long held belief that such molecules can only be handle in situ. Estimated attendance: 25-30.
No symposium on acetylene chemistry would be complete with a talk on click chemistry, and the penultimate talk was delivered by Prof Valery Fokin (Scripps Research Institute), one of the co-inventors of the copper catalyzed Huisgen 1,3-dipolar cycloaddition of azide and alkynes. Following a brief history of the discovery of this reaction, Fokin outlined much of his recent work toward elaborating on the general ability of azides function in this reaction, as well as other that follow a similar mechanistic profile. Much like CJ Li, the protocols outlined in this talk strive for efficiency, and the operative process of this reaction , formally a [3 + 2] cycloaddition, is completely atom economical and can now be catalyzed simple copper foil. Estimated attendance: 35-40.
Finally, an up and coming star in European materials science, Prof Holger Frauenrath (Ecole Polytechnique Federale de Lausanne), took the stage (he was one of the speakers supported by the PRF Grant). While still formally a synthetic talk, the work described by Frauenrath showed how acetylenes, and especially polyynes, can be used to form carbonaceous nanostructures through topochemical polymerization reactions. One target, for example, aims to controllably form parallel graphene sheets that would have incredibly high porosity, thus being suitable for applications in gas storage. A variety of organizational strategies were disclosed toward providing the polyyne alignment requisite for even a reasonably controlled polymerization. While the final products of many of these reactions have yet to be realized, preliminary results offer a tantalizing view of what might be possible for the future of this work. Estimated attendance: 20-25.
