Interview with Professor Sir Jack Baldwin
24 January 2006
Professor Sir Jack Baldwin, FRS
It was Sir Jack's Rules for Ring Closures paper published in ChemComm 1976 that cast him into the chemistry limelight and made him a textbook name in organic chemistry. The rules, which distinguish between two types of ring closure, Exo and Endo, have proved to be an extremely valuable tool for organic chemists ever since. The huge scientific importance of this paper is reflected in the fact that it has been identified as the most cited article in the 40 year history of ChemComm, with more than 1500 citations.
Professor Baldwin talks to Sarah Thomas about this landmark paper, the themes of his spectacular career and what the future holds for chemistry and for Sir Jack himself.
What was the inspiration behind the most cited ChemComm paper, on your rules for ring closure?
I was working on the synthesis of penicillin and wanted to make a five membered-ring, but was not having any success at inducing the ring closure reaction. So I consulted the literature and discovered there were very few successful examples of this type of ring closure that were experimentally proven. When I looked at models I could see it was a stereochemical problem and the required orbital overlap to facilitate the ring closure was stereochemically impossible. I then looked up many examples in the literature and analysis of these led me to formulate my rules which where published in the ChemComm paper. These were followed by further papers showing experimental examples. The success of the paper is that it offers guidance to chemists to help them plan their ring closure reactions.
Why did you choose to publish this paper in ChemComm?
I had always published in ChemComm and even though I was in the US at the time. It was my journal of choice because it is high quality and published communications quickly.
Tell me about the early years of your career
I was at MIT from 1969 to 1978, except for a brief move to King's College in London. The department had a very strong organic section with the likes of George Buchi, Barry Sharpless, George Whitesides, Dan Kemp and later Chris Walsh. The environment was exceptionally stimulating scientifically and we were able to attract outstanding students. In 1978 I moved to Oxford, having earlier been rejected by them as a student when I left grammar school. In hindsight this was not such a bad thing because it meant I went to Imperial College in London where I had the privilege of working with Barton. Some of my first papers were published in ChemComm when I was at Penn State. In particular, I published papers on the [2,3]-rearrangement of sulfonium ylides and subsequently this has proved to be a very general and effective class of reactions.
What have been the strong themes and influences in your research career?
Synthetic chemistry and reaction mechanisms have always been at the forefront of my research interests together with natural products. One of my main achievements, which brought together these interests, was my 20 year project that culminated with the now very well established story of the biosynthetic origin of penicillin, backed up by thorough experimentation. I consider the two most important instrumental developments to have influenced chemistry are firstly, the invention and application of the balance as in Lavoisier's work. This enabled chemists to weigh compounds accurately and know exactly how many atoms were present. The second big development was NMR which has revolutionised the determination of structures. Both techniques rely on the nucleus and not electrons, which makes their interpretation so straightforward and powerful.
What will be the future of chemistry?
The future is good, the science is still relatively primitive. For example, if you set out to make even a simple compound, which has never been made before, you soon encounter problems so there is still a need for new ways to synthesise complex structures. Aside from synthesis, there are chemistry applications in biology, in particular making compounds that interfere in biological systems. The area of nanoscience will also be very important.
What next for Sir Jack?
I continue to run a research group in Oxford. One area of interest is the ultimate in biomimetic synthesis; the origin of life on earth, and what happens following large planetary collisions. Evidence from the Apollo samples show that these contain material similar to the Earth's mantle. I propose that the large collision which formed the Moon brought iron from the Earth's preformed core and that of the collider to the Earth's surface. Iron at the high temperatures of the collision reduced carbon dioxide to carbon monoxide and nitrogen to ammonia, which are basic building blocks for many other compounds which eventually led to life. Thus the Moon-forming event caused a redox change in the Earth's primeval atmosphere which eventually led to the biosphere. This is why in our solar system the Earth with its large moon and its biosphere is unique and suggests that no life will be found on any of the other terrestrial planets. None of them have large moons formed by collision and hence could not generate biospheres. To find other life supporting planets outside the solar system we need to look for terrestrial-type planets with large collisionally formed moons close to a star to provide suitable radiation for the maintenance of life In our solar system Pluto has a large moon but it was probably not formed by collision and anyway is too cold!
What might you have done if you had not been a scientist?
I was always interested in aircraft so I might have joined the air force or been an engineer. When I was in the US I was actually called up for Vietnam. However following an interview before the draft board my services were not required!
What are your other interests outside of science?
I have a life long interest in British motorbikes, although I have just sold my last bike, a 1000 cc Vincent V-twin with a kick start that I bought in 1961. My other main interest is developing and maintaining my large garden.
Sir Jack Baldwin, FRS: Biomimetic studies at Oxford
John E. Moses and Robert M. Adlington, Chem. Commun., 2005, 5945