The synthetic chemist on champagne, art and living in Paris
Janine Cossy is a professor of organic chemistry at ESPCI Paris in France. Her work involves synthesising natural and bioactive molecules, and developing synthetic tools that encompass radical chemistry, enantioselective rearrangements and organometallic reactions. She was speaking to Jennifer Newton
I’m originally from a small village next to Reims in the Champagne area of France. When I was in high school the two subjects I hated the most were English and chemistry. My parents were in the champagne business and I wanted to take over the business, but my father forced me to go to university. Thus, I got my PhD from the University of Reims Champagne–Ardenne and then decided to go to the US for a postdoc [with Barry Trost]. When I came back from the US, I said to my parents ‘now I know what I’m going to do – I’m going to do chemistry’. As I did not want to take the business over, my parents were fantastic with me, they said ‘do what you want, but try to do your best’.
I give my group a lot of freedom. Every 8–15 days, we have what I call ‘confessions’, where each student and postdoc tells me what they have been up to. I’m not so interested in the positive results – negative results are more important because they are about solving problems. You can ping-pong ideas back and forth during the discussion. Sometimes the students and postdocs have unexpected results and this is really exciting, more exciting than expected results. If a PhD student only has positive results that is not good training as in their career they will be in front of problems and they have to know how to deal with them. I want them to be well-trained and do things correctly.
Synthesising complex molecules is kind of a game. PhDs in France are short, they’re only three years, and if you envisage a strategy or synthetic route with more than 35 steps you will never complete the synthesis of the compound in that time. So you need very efficient strategies to get the product, otherwise the students will be frustrated, and me too. I think that total synthesis of complex molecules is a good training for the students – they have to be organised and they need a broad knowledge of the literature.
It’s frustrating when you write a proposal and you don’t get it financed, and even more when you see someone else publish a similar idea in the literature. You think ‘I would have done that, but I didn’t have the money’.
You have two kinds of researchers. The ones who are always looking in the same place and those who are like a fox – always looking all around. I’m more like a fox. I worked on photochemistry for eight years, but I got so fed up with it that I had to switch. At the moment I’m really enjoying organometallic chemistry and working in multidisciplinary projects.
In high school the subjects I hated most were English and chemistry
My colleague named a reaction after me. A Cossy photocyclisation is very simple. You start with alkyl bromides or iodides and use UV light to initiate electron transfer from an amine. So you create an amine–halide exciplex, which leads to a radical and a halide anion. The radical can be trapped very efficiently by unsaturation, or it can abstract a hydrogen atom when no unsaturation is present or a rearrangement can take place. It’s a useful reaction for constructing carbo- and heterocyclic natural and non-natural products.
Being elected to the French Academy of Science was a massive surprise. I received an SMS to say ‘congratulations, you’ve been elected’ and I automatically assumed it was a mistake.
In my free time I like to listen to jazz, take pictures and paint. Chemistry in a way, it’s art. Drawing molecules is not too far away from artistic drawing and painting as the molecules have nice arrangements and are organised into space.
When I was a kid, I dreamed of living in Paris. That dream is now a reality. It’s a very nice city. I don’t go out too often but I really enjoy going to concerts and museums, especially the Picasso Museum, the Musée d’Orsay and the Pompidou Center.
I like to travel; I think I am addicted. I love big cities particularly New York and Tokyo, and I probably know Tokyo better than I know Paris. When you are an invited professor for one month you have time to visit the city better than if you lived there permanently. When I have free time here in France I tend to go back to Champagne.
I don’t like sport, apart from one – sumo wrestling. I saw it on TV the first time I went to Japan and it was really great.
The Japanese are fantastic hosts. I love sushi and sake, but my favourite drink is, of course, champagne – I cannot resist a glass of champagne.
Correction: The article was updated on 3 August 2020 to correct who gave the Cossy photocyclisation its name