Anti-coordination chemistry

To summarize, the naked post-transition element clusters normally present themselves in strongly Lewis-acidic solutions and in solid compounds, which are ionic in the sense that their structures contain large, weakly coordinating anions separated from the cluster cations at van der Waals or weakly bonding distances. The latter fact has given rise to the expression anti-coordination chemistry in connection with such cluster compounds. 

Metal coordination compounds and free metal ions are well known to effect cellular processes This metal effect not only deals with natural processes, such as cell division and gene expression where ions like Magnesium, Zinc and Manganese play a role, but also with non-natural processes such as toxicity, carcinogenicity, and anti-tumor chemistry This chapter deals with a special aspect of medicinal metal biochemistry, namely the mechanism of Pt and Ru coordination complexes applied as antitumor drugs in humans... 

Phenol complexes of [Os] display pronounced reactivity toward Michael acceptors under very mild conditions. The reactivity is due, in part, to the acidity of the hydroxyl proton, which can be easily removed to generate an extended enolate. Reactions of [Os]-phenol complexes are therefore typically catalyzed using amine bases rather than Lewis acids. The regio-chemistry of addition to C4-substituted phenol complexes is dependent upon the reaction conditions. Reactions that proceed under kinetic control typically lead to addition of the electrophile at C4. In reactions that are under thermodynamic control, the electrophile is added at C2. These C2-selective reactions have, in some cases, allowed the isolation of o-quinone methide complexes. As with other [Os] systems, electrophilic additions to phenol complexes occur anti to the face involved in metal coordination. 

Moulder s contention of metabolic similarities would eventually be shown to be incorrect however, examination of the basis for his conclusion allows an appreciation of how concepts and techniques can influence interpretation. In 1944, the United States Office of Scientific Research and Development was created with a Board for the Coordination of Malaria Studies to better understand the mode of action of anti-malarials in order to protect United States troops in Southeast Asia, North America and the Pacific. A member of that Board was W. Mansfield Clark (1884-1964), Professor of Physiological Chemistry (1927-1952) at the Johns Hopkins School of Medicine. His colleague in the department was Leslie Hellerman (1896-1981) whose work focused on metallo-enzyme functions. Hellerman and his student, Marianna Bovarnick (1911-1995), involved themselves in the testing of the biochemical effects of atabrine. Another malaria project was sponsored at Harvard under A. Baird Hastings, chair of the Department of Biological Chemistry, also a member of the Board. Eric Ball (1904—1979) was a graduate student and then a faculty member in Mansfield Clark s department at Johns Hopkins (1930-1939) and spent 1... 

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