Yoshinori Yamamoto talks with
ScienceWatch.com and answers a few questions about
this month's New Hot Paper in the field of
Chemistry.
Article Title: Coinage metal-assisted synthesis of
heterocycles
Authors: Patil, NT;Yamamoto, Y
Journal: CHEM REV, Volume: 108, Issue: 8, Page: 3395-3442,
Year: AUG 2008
* Tohoku Univ, Grad Sch Sci, Dept Chem, Aoba Ku, Sendai, Miyagi
9808578, Japan.
* Tohoku Univ, Grad Sch Sci, Dept Chem, Aoba Ku, Sendai, Miyagi
9808578, Japan.
Why do you think your paper is highly
cited?
Heterocycle synthesis is extremely important to the pharmaceutical industry
and also to the material sciences, in some parts, because most drugs
contain heterocyclic structures. For example, rather old medicines such as
penicillin and vitamins, and the more recently successful drug Viagra,
contain heterocyclic structures. Accordingly, not only chemists in
academia, but also those in industry are interested in new synthetic
methods for heterocyclic compounds.
In addition to the importance of the compounds and structures themselves,
"coinage metal-catalyzed (assisted) reactions" are a newer methodology in
the field of synthetic chemistry. It had been believed that Au, Ag, (and
Pt) are expensive metals and synthetic chemists have not been familiar with
the reagents/catalysts derived from those noble metals.
"...even catalytic reactions, after everything is done,
have to be thrown away—especially in the case of
homogeneous molecular catalysts. This is not a green
process! "
However, entirely new molecular transformations have been discovered using
those noble metals as catalysts. This is another reason why this article is
a highly cited paper; not only practical industrial researchers, but also
pure chemists in academia have had an interest in this paper and also in
this research field.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
Yes, as I mentioned above, entirely new molecular transformations have been
discovered in this research field, which had previously not been possible
through the use of previously known synthetic methodologies.
Would you summarize the significance of your paper in
layman's terms?
Coinage metals (Au, Ag, and Cu) and other noble metals, such as Pt, attract
particular interest from synthetic organic chemists, because those metals
become useful catalysts for synthesizing the core structures of many
important drugs.
Most drugs have heterocyclic structures and those structures can be
synthesized readily and quickly by their coinage metals-catalyzed molecular
transformations, i.e., carbocycles and heterocycles; cyclic compounds made
by only carbon atoms (C) are called carbocycles. Cyclic compounds made by
heteroatoms—such as N, O, and S—and carbon atoms are called
heterocycles.
How did you become involvedin this
research, and were there any particular problems encountered along the
way?
For many years, I have been involved in the research of metal-catalyzed
reactions, but at the beginning of my career, coinage metals (except Cu)
and noble metals had never been included in the general materials of
chemists, primarily because of their expense and the fact that almost no
investigations using noble metals had been done in the past. However, about
10 years ago, one of my students used an Au complex in testing some
reactions. I hadn't told him to use it and I was not even aware that he had
used it.
Later on, I realized that this unexpected use of an Au complex induced a
very interesting molecular transformation. This was the starting point for
my entering this research field. The only problem, even at that time, was
that people believed that coinage metals were too expensive to utilize in
this process, but it is not true, as Pd and Rh are nowadays even more
expensive.
Where do you see your research leading in the
future?
I regularly examine leading journals such as Nature, Science, and
the more specialized JACS/Angew. Chem., in order to be made aware
of which direction the most timely and important investigations are headed.
With my own strong background in the field, I can thereby direct and handle
my research based on the latest findings.
Do you foresee any social or political implications for
your research?
This is an important task for scientists. Nowadays, social and political
implications (or influence) of our own research is becoming increasingly
important to us, and we have to adapt our thinking to this requirement. For
my own research, catalytic reactions are quite important when compared to
stoichiometric reactions, because of the waste problems and energy savings.
However, even catalytic reactions, after everything is done, have to be
thrown away—especially in the case of homogeneous molecular
catalysts. This is not a green process! Nowadays, to undertake a solution
to the environmental problem, we will have to create a catalyst for a
greener process. This will be my next research target.
Yoshinori Yamamoto, Ph.D.
Director, WPI-AIMR (Advanced Institute for Materials Research)
Professor, Department of Chemistry
Graduate School of Science
Tohoku University
Aobaku, Sendai, Tohoku, Japan Web |
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