chapter 2 palladium catalysts in suzuki cross- coupling reaction

TBAB delivers Br - ion to anionic palladium species; [Br-Pd-ligand] - to activate Pd
(Amatore and Jutand 2000).
2.2.2.6. Solvent and Temperature Effects
Most of typical reaction components like aryl, allyl or benzyl halogenides and
their coupling products are very sparingly soluble in water. So, most of these
components are realized in organic solvents. The Suzuki-Miyaura cross-coupling
reactions generally employ organic solvents such as THF and diethyl ether in the
presence of Pd(II) or Pd(0) catalysts which are soluble in these solvents (Kotha et al.
2002, Paetzold et al. 2001).
Although the solubility of the majority of organic compounds is low in water,
from industrial and environmental points of view, the reactions performed in water are
desired. Because the use of water as solvent is safe and inexpensive. In literature, there
have been several examples related to the Suzuki reactions carried out in water (Uozumi
et al. 1999, Li et al. 2000, Paetzold et al. 2001, Sakurai et al. 2002, Baleizao et al. 2003,
Baleizao et al. 2004, Shimizu et al. 2004, Jang and Ragauskas 2006).
Reaction temperatures of the Suzuki reaction range from room temperature to
140 °C.
2.2.2.7. Pressure and Microwave Heating Effects
Microwave-promoted synthesis is an area of increasing interest in both academic
and industrial laboratories. Although people had been using microwaves in their homes
for many years, it was not until 1986 that the first reports of microwave-heating in
organic synthesis appeared in the literature. As well as being energy efficient,
microwaves can also enhance the rate of reactions and in many cases improve product
yields. Also, many reactions can be performed by using microwave heating that cannot
be achieved by using ‘conventional’ heating methods (Leadbeater 2005).
Recently, Arvela et al. have shown that by using microwave promotion and
water as a solvent, the Suzuki reaction of potassium organotrifluoroborates with aryl
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