Page 64 - Visions of the Future Chemistry and Life Science

World champion chemists 53

chemistry than the direct application of quantum mechanics. A computer
may do better to read Pauling than to solve Schrödinger if it wishes to con-
tribute to the development of chemistry.
A huge amount of information has been built up by chemists over the
last century which is directly useful for solving new problems in organic
synthesis. The difficulty lies in retrieving the right information to help
with a specific problem. This may simply be finding one piece of informa-
tion, for example, a particular reaction which has already been done in a
similar way, or it may be finding two or more disparate pieces of informa-
tion which add together to give a better knowledge of what may happen in
a new reaction. The advantage of having a large amount of data at chemists’
disposal is also a problem. How can this data be handled effectively?
The textual content of chemistry papers can easily be held in a data-
base, and searched for key words. More sophisticated procedures may also
be used, to search for groups of words which tend to appear close to each
other, so enabling relevant papers to be discovered. However, chemistry
papers are written in many languages and even chemical names are not
used consistently. The international language of organic chemistry is
structures, such as those drawn in the figures in this article, and these
contain more information than can easily be manipulated in words. In the
past few years, computers have become sufficiently powerful that an ordi-
nary desktop machine can draw chemical structures, and be used to search
a database of structures. This has revolutionised the way that the chemi-
cal literature is used. Instead of having to translate a structure to a name,
and then search a printed index of chemical names, in order to find refer-
ences to abstracts of papers, it is possible to sketch the structure, or trans-
formation, of interest and be presented with an abstract, or a diagram, or
even the full paper which uses the structure.
Such techniques mean that the chemical literature may be used more
effectively, and that its use can be partially automated. Might this lead to
a way of automating organic synthesis? To make most molecules there are
many strategies which may be successful. If each reaction of each strategy
can be evaluated for similarity to a reaction recorded in the literature, it
should be possible to develop a route to most molecules by mechanically
searching the chemical literature, so that suitable precedent is found for
every transformation.
There are two difficulties with this approach. First, there is the
problem of performing all of the necessary searches. As discussed above,