Aqueous solutions organometallic chemistry

Behr, A. Technical Solutions. In Aqueous-phase Organometallic Chemistry Cornils, B. Herrmann, W. A., Eds. Wiley-VCH Weinheim, Germany, 1998 pp 163-180. 

This is also a field of chemistry, where biphasic and phase transfer-assisted organometallic catalysis [11-12] are very close and sometimes may even overlap. One reason for this closeness is in that inorganic bases are often used in aqueous solutions. Of them, OH is so strongly solvated in water that it will practically not transfer to non-polar organic solvents without a phase transfer (FT) agent, e.g. a quaternary ammonium cation. However, some reactions proceed readily with H2O dissolved in the organic phase, or can take place with reasonable rates at the liquid-liquid interface, and in these cases addition of FT catalysts is not essential. 

The past four years have been characterized by more and more diverse applications of aqueous organometallic chemistry for the synthesis of fine chemicals. Useful classical transformations have been realized in aqueous solutions. The recycle of the transition metal catalyst has sometimes been possible, but the main importance at this early stage lies in the reactions themselves. 

In contrast to the foregoing examples, preparation chemistry on a support surface is often analogous to coordination chemistry in aqueous solutions rather than to organometallic chemistry in organic solutions. Aqueous chemistry is much more typical of the preparation of industrial catalysts than... 

Another area of ROMP in the early stages of development is the polymerization of highly functionalized monomers in protic and aqueous solutions. These catalysts appear to tolerate most organic functional groups and will polymerize highly functionalized monomers (equation 16). The development of the organometallic chemistry of these catalysts will open a variety of new applications of metathesis in organic synthesis. 

The current review is concerned mainly with the advances in thallium aqueous solution chemistry during the past 25 years. The chemistry of thallium in organic and organometallic chemistry has been covered by several recent review articles and book chapters (13, 23-30, 52) therefore, this subject will not be discussed here. The coverage of the literature will be extensive but not exhaustive. Also, since it is not possible to satisfactorily cover all work on this subject published during the time period within the scope of this review, the choice of the material is admittedly infiuenced by the scientific interests of the reviewer. 

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