New Synthetic Methods Group
Overview
of our research
Our research is focused
around the development of new ways to do synthetic chemistry. We are
particularly interested in doing chemistry in a clean and efficient
way. Our research is spread across organic, organometallic and
inorganic chemistry with overlap between the different areas. Our main
research topics are outlined here.
Chemistry using microwave heating and water
The area of
microwave-assisted chemistry is very new and exciting and is becoming a
hot area for research both in academia and industry as evidenced by the
number of publications appearing in the scientific and patent
literature. Just like in the home, the attraction of microwave ovens is
the fact that they offer a cheap and easy way of heating very fast. As
a result, microwaves can enhance the rate of chemical reactions,
reducing times from hours to minutes. In addition the use of microwaves
is opening new avenues of chemistry. Research in our group is focused
on the use of microwaves for organic and organometallic synthesis. We
use state-of-the-art scientific microwave systems, these allowing us to
control the reaction conditions very precisely.
Projects:
Development and exploitation
of ultra-low catalyst concentration coupling reactions
Fast, new, clean organic
synthesis in the microwave using water as a solvent
Organometallic chemistry
using microwave promotion
Use of our microwave
methodologies in design and synthesis of molecules that impact on
biology and medicine
Literature:
Suzuki coupling of aryl
chlorides with phenylboronic acid in water, using microwave heating in
conjunction with simultaneous cooling Org. Lett. 2005, 7, 2101
Microwave-promoted Heck
coupling using ultralow metal catalyst concentrations, J. Org. Chem.,
2005, 70, 1786
A reassessment of the
transition-metal free Suzuki-type coupling methodology, J. Org. Chem.,
2005, 70, 161
Rapid, easy cyanation of aryl
bromides and chlorides using nickel salts in conjunction with microwave
promotion, J. Org. Chem., 2003, 68, 9122
Rapid, easy halide exchange
in aryl halides, Synlett, 2003, 1145
Chemistry in ionic liquids
Ionic liquids are a new class
of solvent that are attracting a great deal of current research
interest. They are very polar molecules that are liquids at room
temperature. They have negligible vapour pressure and are stable up to
high temperatures. All these factors make them very useful as potential
solvents for microwave chemistry. We are able to do chemistry at very
high temperatures and very fast in these ionic liquid solvents. Using
our microwave system, these solvents can be heated to around 200
– 300 °C in a few seconds and reactions that would otherwise
take hours can be complete within 2 – 3 minutes. This work ties
in with our chemistry in water and the members of the group working in
this area have developed their chemistry together with those working
using water. We have developed a method for preparing large numbers of
compounds very easily and rapidly using the ionic liquid / microwave
heating methods. This sort of chemistry, called combinatorial chemistry
or compound library synthesis, is of particular use in the
pharmaceutical industry where people want to maker lots of compounds
rapidly so they can be screened for biological activity.
Projects:
Catalysis using ionic liquids in conjunction with microwave
heating
Preparation and use of designer ionic liquids
Enzyme catalysis in ionic liquids as solvents
Literature:
A study of the ionic liquid mediated microwave heating of
organic solvents, J.
Org. Chem., 2002, 67, 3145
Ionic
liquids as reagents and solvents in conjunction with microwave heating,
Tetrahedron, 2003, 59, 2253
Organometallic synthesis using
photochemistry
Using photochemistry it is
possible to overcome barriers to reactivity that would otherwise
involve the use of high temperatures or pressures. As a result it is
possible to do chemistry at room temperature or below. In addition,
photochemistry offers a very selective way to make molecules. We have
been exploiting these advantages for the synthesis of metal containing
compounds. We have managed to prepare a number of new molecules this
way that it is not possible to make using conventional methods. More
recently we have been focusing on using photochemistry to prepare
metal-containing polymers of known and precise length and composition.
This is of interest to the polymer industry since the possibility of
producing designer polymers is very attractive.
Some of the organometallic complexes we have made are shown
below
Projects:
Use of photochemistry to make new
organometallic architectures such as molecular cubes
Use of photochemistry to make new
organometallic polymers
New ways to make organometallic complexes:
Polymer-supported organometallic chemistry
Literature:
Preparation of
resin-bound metal carbonyl reagents and preliminary demonstration of
their use, Inorg. Chem., 2003, 22, 4167
Preparation of
polymer-supported ligands and metal complexes for use in catalysis, Chem.
Rev., 2002, 102, 3217
Photochemically generated
organometallic molecular square Complexes, Inorg.
Chem., 1999, 38,
4149
Photochemical synthesis of organometallic oligomers of
defined composition and length, Macromoecules, 1999, 32, 4450
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