Transcript from an interview with the 2010 chemistry laureates
Transcript from an interview with 2010 Nobel Laureates in Chemistry, Richard F. Heck, Ei-ichi Negishi and Akira Suzuki on 6 December 2014. The interviewer is Adam Smith, Editorial Director of Nobel Media.
Richard Heck, Ei-ichi Negishi, Akira Suzuki, welcome to Stockholm and Nobel week. Professors Negishi and Suzuki, you have just arrived from Japan where you were together, being feted. Do you enjoy all the attention that this brings?
Akira Suzuki: Well, I think maybe I want to enjoy it. How about you?
Ei-ichi Negishi: I feel that it’s part of the prize and probably the best thing is for me to enjoy it and provide hopefully my best service too.
It’s true, you can’t escape, you might as well enjoy, yes. How about you Professor Heck? You were in the Philippines so maybe that was a little quieter.
Richard F. Heck: I have already retired so yes, nobody found me there. It was quiet.
You already, I suppose, must be used to some fame anyway because the reactions, for which you have been awarded the Nobel Prize, are named after you, there’s the Heck-reaction and the Negishi-reaction and the Suzuki-reaction. So, you are household words in any chemistry laboratory.
Ei-ichi Negishi: Only in the chemical world.
Yes, but within the chemical world, very important world, there is so much of carbon-carbon chemistry is done using these reactions. It’s a nice part of chemistry, organic chemistry, that the reactions named after their inventors. So, all these characters live on through the pages of the organic synthesis textbooks. Do you know where that convention came from, that reactions should be named after the people who made them?
Ei-ichi Negishi: No, I don’t, but there are several books based on so-called name reactions and I had an occasion to go through some of them and after the World War II, there have been just about 100 names, given to 100 reactions. So that means maybe two per year.
It’s getting much rarer.
Ei-ichi Negishi: I’m not sure, so, I suppose we are three lucky ones.
Akira Suzuki: Of course, before the second World War, some of the small numbers of the name reactions, we already had. For example, Diels–Alder-reaction, that kind of reaction has a very long historical background, but as Ei-ichi just told you, after the second World War, I don’t know why, because one reason should be, many reactions were discovered by many organic chemists. That should be one reason and another reason is, name reaction is very convenient, for example in my case, if I tell you exactly in the chemical words, that is a cross coupling reaction of organoboron compound, with organics electrified. So, that is so long word, but the Suzuki-reaction is very including all of such things. So, I think Professor Brown, because I just talking about when the ability …
When I meet Professor Brown, Herbert C. Brown, he recommended me like to my so-called Suzuki-reaction. So, I agree, I started to write such a book and finally I named the book ‘The cross-coupling reaction of the organoboron compound’. Professor Brown said, No, this is not a nice name, Suzuki-reaction is the very simple and the very convenient. But I was against his proposal, because I’m one of very small, shy Japanese chemists, so I don’t like such a big name, reaction about joint named reaction, but Professor Brown said No, no, it’s ok. But at this moment, I completely thank to Professor Brown because he gives me … I just … We decided, I publish my book. The title of the book is The Suzuki-reaction. That is a very … now I’m very thankful to Professor Brown because it’s very convenient to collect all of such a research from the Suzuki-reaction and cross coupling reaction. Everything I can collect such a chemistry. It’s convenient.
It’s a nice way to be made immortal to have a reaction named after you, I think. If we turn to the cross-coupling reaction we’ve just being discussing. It began with you, Professor Heck, in working at Hercules company, I think, and you were exploring palladium’s ability to do interesting things. You weren’t actually looking for a cross-coupling reaction?
Richard F. Heck: No, I wasn’t, it just happened. I recognised it and I thought it would be something useful so that why I studied it.
When you publish papers on this, you publish them as a single author, which implies that you were working very much alone, was that the case?
Richard F. Heck: Yes. Well, I had a non-technical assistant, but I only had to put my name on it.
Were you left free to play in this industrial environment?
Richard F. Heck: I was in their basic research group, just a small group that could try anything, I guess, if they thought it might be useful. They left us alone pretty much, at least for a while.
And were you aware that palladium would act as a catalyst to bring carbon atoms together in this way?
Richard F. Heck: Well, there were some things in the literature that suggested it might a be useful reagent for doing that kind of chemistry, yes. There were some early people in this field who did some good chemistry, like Koetz, remember? Koetz and Calvin, I remember those people, which was one very early but nobody seemed to follow it up.
Was your company keen to make money out of your research?
Richard F. Heck: That is was what it was supposed to do, I don’t think I did much for them, but that’s the reason for why I’m not there anymore.
You weren’t patenting the method or anything like that?
Richard F. Heck: They patented everything that they thought could possible conceivably be useful, so some of it was patented I think.
But it didn’t stop everybody just taking it out.
Richard F. Heck: They didn’t seem to care whether they did it or not.
The beauty of the Heck coupling-reaction is that it’s a relatively mild way of putting carbon atoms together and therefore it’s hugely applicable because you can leave all sorts of side groups intact while doing it.
Richard F. Heck: Yes, leave the functional groups alone.
Its uptake … now, these reactions are everywhere, but the uptake wasn’t immediate?
Richard F. Heck: No, it’s usual … isn’t it?
I guess, but when do you think its power was seen?
Richard F. Heck: I couldn’t put a date on it. It’s a slow process, it just happens slowly. To make a decision on when it started, I don’t know, it’s hard to say.
And then Professor Negishi, you replaced the olefin part, the carbon-carbon double bonded part of reaction with an organozinc compound. And this extended the applicability of the reaction.
Ei-ichi Negishi: I guess, I represent a rebellious group, so basically what we have done is, took a queue from his reaction, replaced the hydrogen, CH, with a CM, so this is … Many people nowadays say, “You went backwords”, because hydrogen is a more agreeable element generally concerned to be a more agreeable element, than metal.
So, you made it more toxic.
Ei-ichi Negishi: Potentially. But some of us, including myself, say, this is characteristic of sort of a next generation group including Professor Suzuki’s Suzuki-coupling. If I may say so, it’s a tag, M is a tag to organic molecule. So here, you shall react here or here or here, we can specify, cis and trans, here or here, cis or trans and such. And it will also act as a major promotor, having M, rather than H. Eventually, I think, we would want to go back to hydrogen again, but at the moment, we claim that by replacing original hydrogen with metal, now the rest can be virtually anything. And then with a tag and speeding up the reaction, from around 100 degrees down to room temperature or below and then retaining all sorts of integrities of that group, we can specify cis by putting M in a cis position or we can specify trans by placing M in a trans position. So that’s a rebel.
But it’s very interesting to hear this reaction talked about as a work in progress, that there is a current situation where you are dealing with CM, there is an eventual position where you perhaps can go back to CH, because when I think they are talked about normally, as if they are things that have been given to the community, and this is the Heck-reaction, this is the Negishi-reaction, this is the Suzuki-reaction and they are to be used and one doesn’t think about their further development, but of course, they are developed with each other and there is a continuation.
Ei-ichi Negishi: I think that is our ambition, and our eventual goal is to be able to hook together any two organic groups and we believe that we have covered a little more than halfway through for this goal. But in each case, as I said, eventually it would be very nice to replace metal with hydrogen, but to what extent we can do is a remaining question. But before that, we want to be able to cover all types of organics and all combinations, probably we have to take care of about 100 different combinations, and I believe we have reached just about a halfway point.
I want to pick up on this halfway point, because there is this marvellous abundance of molecules out in nature, that we look at and try to emulate and sometimes build and sometimes try to improve upon and then there are textbooks full of reaction schemes which allow one to think about how to put things together to make them. And you’re saying that we’re about, as an estimation, halfway towards the goal of filling those textbooks to the absolute limit. How does one estimate how many reactions there are to be discovered?
Ei-ichi Negishi: Halfway means not necessarily in sort of a volume of things that we cover. Typically, organic compounds, we can consider in terms of ten or so dozen different kinds of functional groups – alkyl, alkene olefin, acetylene, aromatics, acyl, etcetera. About ten or a dozen. If you take a look at the organic chemistry textbook, then you see their discussion, discussions of them, in a dozen or twenty chapters, so that’s organic chemistry. If you consider ten or so as R1 group, and then similar ten or so, as R2 group, then you have ten times ten, a hundred combinations. If you can hook them at will, as you wish, then that’s the whole organic framework construction. You understand? Forget about other functional details but in this, in our approach, functional groups can be there, can be placed as needed. And then, when time for coupling the two together, we do that.
It makes organic chemistry sounds so lovely and approachable, the ten-by-ten matrix and that’s it. If you can fill all the boxes in …
Ei-ichi Negishi: I call this “Lego-game”. You know, two Lego-game pieces, then you hook them and there the critical one is palladium.
So that acts as the catalyst, that is the thing that brings the Lego-pieces together.
Ei-ichi Negishi: That’s the main difference between what we do and what Grignard did 100 years ago, when he won the Nobel Prize, the first Nobel Prize in organometallic chemistry. He didn’t have the catalyst, but his is probably still considered to be one of the most versatile methods in organic synthesis and I tend to feel that ours might supersede, might go beyond.
And that’s because of the power of the transition metals to catalyse. Tell me about the power of the transition metals, here we deal with one, palladium, but there are …
Akira Suzuki: According to my opinion, I have a little bit different thinking about chemistry. This time, I don’t know, we get the Nobel Prize by using the cross-coupling reaction, using the palladium catalyst, but according to my opinion, palladium is not the only important transition catalyst because palladium is, of course many people know palladium as a very nice catalyst, but unfortunatelyit is a very expensive. So, nobody wants, especially in the company, they don’t want to use such an expensive catalyst for a big amount. So, recently for example, in our reaction, using organoboron compound, of course we, when we started our chemistry, we first used the palladium catalyst, but not only the palladium, we also used the nickel compound and other kind of transition metal compound. But at that time we found palladium gave us the best result, nickel gave us the some result, but sometimes they had a mixture of product selectivity, that means selectivity’s no good, so I decided to a student, we stop to studying other transitional metal catalyst except the palladium.
We started, we only checked the reaction using palladium compounds. But after that … many people use palladium catalyst in our coupling reaction [but they do] not always give us the best result because when we use the palladium compound for example, the coupling reaction of aromatic chloride, with aromatic /- – -/, it’s very difficult when we use a palladium compound. But recently, people reported when we use nickel compound as a catalyst instead of the palladium compound even the aromatic chloride reacts with the aromatic /- – -/ to give a different type of compound, that is one of the big advantages.
So, as well as varying the substituents that goes into the reaction, one can also vary the transition metal catalyst and then that just opens up a whole new spectrum of possibilities. The idea that we can solve all these problems of how to link the different functional groups together, suggests that there might be an end to the development of organic chemistry, that organic chemistry, the synthetic methodology, could reach a point which you say right, it is, we have what we need and then it just building what we need. Do we really foresee such a time?
Ei-ichi Negishi: In a very, very long time … This is only one mode of organic synthesis, very, very general, very important mode, but I have been recently telling people, organic synthetic chemists have a major, major task right now which we want to solve. That is, how to convert carbon dioxide and water into carbohydrate, which nature does in a biochemical way, biological way. But no synthetic chemist has yet to claim this laboratory way, or factory way, of doing the same thing. I think this is a very, very important task because if we can do that economically, which we should be able to do, then we will solve a food problem, energy problem and a pollution problem, because CO2 is a starting material, we need more rather than less. And I cite this one because I believe, firmly believe, as in nature, D-block transition metals, in the case of biological process, it’s iron, iron is a D-block transition metal. It is going to be critically needed, probably one electron transfer process, radical kind of chemistry, rather than our nice two electron transfer processes, like the Heck-reaction or the Suzuki. Because there are two electron transfer process reactions.
So you would promote the study of and research on the D-block transition metal as a major area?
Ei-ichi Negishi: I’m just presenting this as an example of a major goal, right in front of us. We want to solve this today or maybe in a year’s time or ten years’ time and no one right now we have a feeling that we should be able to do that because nature does, nature has been doing that for billions of years. It’s a big shame for the entire group, including ourselves. What I’m saying is that, this is just one of the major pending goals. You talked about our tasks being reduced, eventually to zero. I don’t think that time will come pretty soon.
When you moved into organic chemistry as a young man, was it the desire to solve problems such as how to convert CO2 or other things that drove you there or was it general inquisitiveness, were you applied or just curious?
Richard F. Heck: I enjoyed working with chemicals, I do things and make all kinds of perfumes and things that interested me in my first few years of my studies and I expanded on that and it’s useful to make all kinds of materials that you might want to use, technical materials for example.
Where you a childhood chemist?
Richard F. Heck: Yes, that was in my early teenage years I started chemistry.
A lot of children make bombs when they are children.
Richard F. Heck: Well, I guess I did do a little of that, but not much. So that was my start.
What about you Professor Suzuki, what lead you to chemistry when you were young?
Akira Suzuki: Well, I think, recently I don’t know … as a young student in Japan … people say young Japanese boys and girls they never feel so much interest in the science, including the chemistry, physics and so on. But, so this time, after I get the Nobel Prize, decided I received the Nobel Prize, I have a main chance to talk with press people, they say in Japan, the young people they don’t like science and technology, but I think, in Japan of course as you know, in Japan we don’t have any enough resources. We don’t have any petroleum, not have any iron resources, we only have coal mining resources but that is located so deep under the ground, so it takes lot of money to cut from down to up. So, in Japan the important thing is, we, they make a very nice product, then we sell such a product to all over the world. That is the only way Japan people, we continue our country, in such a meaning, we have to say to young people, you have to explain our situation. And one way we can continue our Japan is, to feel very much interest in science and technology, to make very nice products to sell to the world.
In such a meaning, I say, the Japanese government and the professors, we say such a thing to the younger people and he join us to pay much interest in our chemistry, not only the chemistry, the science and the physics. But in such a meaning, I always say, the other day, I got the chance to talk with Prime minister of Japan, after I received the Nobel Prize, so I emphasised this thing to our Prime minister. He is also a scientist, physics is his major, so he understands very well, but unfortunately many of the people in our government, don’t understand very much more of science and technology, so I think it’s important in the government to understand such a situation and to give lot of research money. Of course, at this moment, Japanese, our economical situation is very, not so nice, even though I asked the Prime minister our government understands such a situation to support the science and the technology and to give research money for such a field and also reasonable money to the education That is very important. I just say such to government people recently.
It’s obviously undoubtedly good for society that scientists, the young people move into the science. Normally such aims are not the thing that drives people into science, you realise that later, but as a young person you are just probably following your curiosity.
Akira Suzuki: I don’t know but anyway, I just explain the Japanese situation, but what are the situation here in Sweden or here in England, here in United States – is the same thing?
Richard F. Heck: So many different people in groups, it’s hard to get one single view of things. I think there are many different approaches.
Akira Suzuki: But my friend American says the young people they like very much to become medical doctor and lawyer. That is just connected to some money. That is a very serious problem, I think. We have to emphasise, we have to give the advice to young people; money is not the only one thing we have to consider, but anyway.
That’s a good message. I don’t suppose that is was money who drove you to chemistry originally? What was it that made you adopt chemistry as your subject?
Ei-ichi Negishi: Well, as an elementary school kid, I liked maths, very crisp. Then I thought I was going to major double E, electrical engineering, fascinating electronics, then I switched to chemistry, perhaps a little bit for money, because someone told me in electrical industry, the pay is not so good. So, my motivation was very impure but looking back I think that I chose the right field for me, because it’s not so mathematical, you know, it’s not like maths, it’s not cut and dry. And yet I didn’t develop my liking towards biologically oriented areas, because there were so many unknowns, so many nebulous kinds of things, many things were so in between, so they didn’t appeal to me. And now chemistry is sort of in between, between two extremes and I love that and I think this is an area where we can exercise our imagination and we can have many useful discoveries and development and then overall impact is, the works for the benefit of mankind. So, looking back I am very glad that I chose chemistry and I am recommending this to many young people, by saying that.
Sort of feet on the ground and head in the air. Do you find young people are coming to chemistry to a sufficient degree in the States? You have been teaching in Purdue for many years, do you find that?
Ei-ichi Negishi: From our perspective, probably we are finding fewer and fewer younger people to be sufficiently qualified to be trained by us at the graduate level, that’s what my main interest is in and that’s been one of my concerns.
It’s no longer seen as a better paid alternative. Why do you think they are not coming?
Ei-ichi Negishi: As you said, probably they are gravitating towards the areas that obviously look more lucrative. One of my grandchildren, he is major in business, not chemistry, not science, maybe for that reason.
I think you used the phrase, shortly after the award of the Nobel Prize, that you see the development of the work you have been doing in the organometallic chemistry as searching for the truth and that has to be an extremely appealing concept for any young person, but maybe chemistry is sold wrong, maybe people coming in to it, don’t see it that way.
Ei-ichi Negishi: Probably not, it takes some experience and experience of discovering something new or in a sort of a rigorously scientific way, you make some developments. And these kinds of experiences will further excite you to prepare you to pursue along the line and those are very, very exciting experiences, even today.
I suppose you have to have the rigour before to get the joy to discovery and that …
Ei-ichi Negishi: It seems that way, yeah. And in my case, perhaps in Professor Suzuki’s case, we learned a lot of these kinds of things, how to manoeuvre through failures and difficulties and eventually to come up with a success from our common mentor, Professor Brown.
Let’s return to Herbert Brown, Professor Brown, what was it that he taught you?
Akira Suzuki: I think, he gave us many things, one thing I still knew about that he said that is, “You have to study, your research leader should be in textbook”. So, that means, you have to find your chemistry just new field of the chemistry, so, if such a new chemistry should appear on the textbook, so he always says you have to do your study which appears in the textbook. And also, I often say, the thing is a little bit different, but I always say to students, you have to do the basic, in Japan we have a special box. In the box we put the rice, how do you say in English? That is a kind of the rice box or something like that.
Akira Suzuki: Yeah. So, I say to students, you never do your study just inside of the box, just pick up some rice or something like that, no that is not our research purpose. Our research purpose is, even if your rice box is small, you have to make the new rice box. That means that you have to define a new research, nobody tried such a field. That is the meaning of the almost same meaning Professor Brown told us and I told my student. So, I always emphasise to students, you have to find the new research field in our study.
People are very keen these days in saying that you should think outside of the box. But this is much nicer, because you don’t just think outside of the box, you have to create a new box. It includes the discipline one requires not just the kind of wildness.
Akira Suzuki: Yes, yes, that is my, Professor Brown and I, in such a meaning we had the same feeling, I think. He said, he was young, he liked mathematics first. But myself is almost the same. When I was a high-school boy, I feel very much interest in the mathematics, so when I get in the university, Hokkaido University, first I did the studies of chemistry in the department of mathematics, /- – -/ science, but at that time when I learned organic chemistry, our professor, the textbook, we used the textbook of organic chemistry, written by Professor Fieser, he used to be professor at Harvard, Boston, United States. That is very, very interesting, so I changed my major from mathematics to organic chemistry. Organic chemistry is of course one divisionof chemistry, but the organic chemistry is so far from the mathematics. Physical chemistry is just near the physics and the mathematics. Organic chemistry is so far, I changed so much my intention.
Herbert Brown was obviously an enormous influence on you as well, Professor Negishi. Is there something in particular that you remember about him that encapsulates his approach?
Ei-ichi Negishi: There are many, many, but I think he is a master of how to handle difficulties or failures and turn them into success. And I believe we all learned how to deal with those hard situations, and he had many, many, so usually he had so many plans.
I suppose that failures are really more frequent than success in science.
Ei-ichi Negishi: It seems that way, but in his group the ratio of success to failure gets very high and I eventually came up with my own saying for my group members. I say, “Research is something in which we link success with success with success with success”, in other words, when we fail, we do it in Brown’s way and minimise the time of failure or difficulties and turn that, or switch, to success. And I think we need to have of this kind of intense attitude, maximising success to failure ratio, as Brown did and because we have the same amount of time every day, every year in our lifetime, pretty much the same. I benefited, I have benefited greatly from that sort of attitude and that approach.
And last, Richard Heck. Working alone, maybe you didn’t have a mentor, or was there somebody?
Richard F. Heck: I worked with Winstein first where I got my degree and he taught me physical organic chemistry and I didn’t follow that up, I got into more organometallic chemistry as I went into industry. So, in industry I tried to make money for the company mostly so they were directing my work more or less.
And then when you were teaching at the University of Delaware what did you trying to impress upon the students? Was there one message summed up your …
Richard F. Heck: Well, I guess what they came away with, it’s a difficult subject and you’ve got to study hard if you want to do well in chemistry.
That seems like a good admonition to end the interview on. Thank you very much indeed all of you for speaking to us and I wish you the most pleasant of Nobel weeks. Thank you.
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