Postagens de Rogue Scholar

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Publicados in Henry Rzepa's Blog

Recently, the 100th anniversary of the birth of the famous chemist Derek Barton was celebrated with a symposium. One of the many wonderful talks presented was by Tobias Ritter and entitled “ Late-stage fluorination for PET imaging ” and this resonated for me. The challenge is how to produce C-F bonds under mild conditions quickly so that 18 F-labelled substrates can be injected for the PET imaging.

Publicados in Henry Rzepa's Blog

All organic chemists are familiar with the stereochemical notation for bonds, as shown below. But I had difficulty tracking down when it was introduced, and by whom. I offer a suggestion here, but if anyone reading this blog has got a better/earlier attribution, please let us know!

Publicados in Henry Rzepa's Blog

Most scientific theories emerge slowly, over decades, but others emerge fully formed virtually overnight as it were (think Einstein in 1905). A third category is the supernova type, burning brightly for a short while, but then vanishing (almost) without trace shortly thereafter.

Publicados in Henry Rzepa's Blog

The diagram below summarizes an interesting result recently reported by Hanson and co-workers (DOI: 10.1021/jo800706y. At ~neutral pH, compound 13 hydrolyses with a half life of 21 minutes, whereas 14 takes 840 minutes. Understanding this difference in reactivity may allow us to understand why some enzymes can catalyze the hydrolysis of peptides with an acceleration of up to twelve orders of magnitude.