So, if you've been reading the chemical literature much in the last 5 years or so, you've probably noticed the ongoing explosion of papers on the topic of Photoredox chemistry. It seems that organic chemists in the field have been borrowing increasingly bizarre transition metal complexes from the electroluminescence, photophysical and materials literature for some time now, and keeping track of them all is a real pain. I mean, how many people can draw from memory the structure of that Bernhard Ir(4',6'-dF-5-CF3-ppy)2(4,4'-dtbbpy)PF6 catalyst from the latest MacMillan group paper? Don't look at me like that—it's commercially available from Aldrich. And you can remember its oxidation potential, right? Versus the Saturated Calomel Electrode? In the Ir(iii)* excited state and as Ir(iv) after reductive quenching?
Well, if this isn't your area of expertise, help is at hand. A friend recently emailed me this handy series of common photocatalysts apparently assembled by Daniel DiRocco at Merck, which I thought it would be worth sharing more widely. Hopefully DiRocco won't mind – it's pretty darn useful and I've seen it a couple of places online already.
*Alternatively, here's a better quality version as a PDF. I hear it looks nice printed to A3 if you can manage it.
2. You probably saw him most recently as lead author on that awesome Merck photoredox-Minisci heterocycle alkylation paper in Angewandte earlier in the year: Daniel A. DiRocco et al., Angew. Chem. Int. Ed. 2014, 53, 4802 –4806.
In the four months I spent not writing this post, the Paterson–Dalby synthesis of jiadifenolide was covered over at Synthetic Nature, but as I’d already put a few hours into it I decided to use the Christmas holidays to dust it off and finish it up. Enjoy! —BRSM
Total Synthesis of Jiadifenolide
The second synthesis in this two part series on jiadifenolide comes from the lab of Ian Paterson at Cambridge University in the UK, although it seems that Steven Dalby (now at Merck, Rahway) had enough of an impact on the work to also be named as a corresponding author. Like Sorensen’s approach, the British team also chose an “A-ring first” approach to the target, but instead of dipping into the chiral pool they instead built it up from simple 3-methyl-2-cyclopentenone through some clever use of a couple of highly diastereoselective rearrangements.