The latest addition of Specialty Chemicals Magazine (November 2014 pp 26-28) features a perspective on flow photochemistry today and tomorrow- both, the process and available tools or light sources needed to operate at the gound state, but also at an excited state (single and triplet state). If interested, I have posted my thoughts on expanding capabilities in flow chemistry. Before highlighting a couple of reactions, I wanted to point out the Duncan Guthrie does an excellent job of setting the mindset that one should enter with for thinking about photochemisty. He talks about the fact that 1% of the total reaction availability is accessed through photochemistry over the years, but that a number of these can be utilized and expanded through use of the appropriate light source and the sustainability of flow techniques — I agree. Duncan then goes on to express that these processes should be embraced by the non-photochemical expert and can be easily performed as a skill developed by performing an extension of normal ground state flow methods…..again, I agree with this sentiment. It can be viewed no different from adding hydrogenations to your arsenal having not done one before…as easy as that, not to mention that re-educating the number of chemical transformations that can be added by opening up this capability.
The article is reasonably short and if you are a synthetic organic chemist, you should dig into the article — a few examples are shown from the article to illustrate the point:
Pericyclizations of the benzamide under flow conditions.
Publication out of the Seeberger group shows divergent continuous-flow photochemical methods toward Arteminisin-derived targets as an example of broadening application of flow and photochemistry in natural product synthesis:
One last point, the filtering of light sources is well defined when application and technique is detailed….as well as the utility of the cooling process for the type of flow technology. Enjoy the article, because the implications provide a broadening of several industries and research. Happy Reading!