Organometallic compounds hypervalency

Structure optimization of main group molecules with generic force fields has the same advantages and problems as molecular mechanics calculations of organic and organometallic compounds with similar approaches on one hand there is no need to fit a specialist force field, on the other hand is the expectation of lower accuracy1279,2801. The structural results are especially poor for molecules where electronic effects are important, e.g., those with hypervalent or dative bonds. 

As already discussed (Section 5.2.3), a-metallated ketones were converted by IOB into a-methoxyketones, in presence of methanol. Generally, various organometallic compounds react readily with hypervalent iodine reagents undergoing an umpolung of reactivity the intermediates formed need not be isolated, since they may react in situ with a variety of nucleophiles. A simple example illustrating the point is the... 

Much attention is also paid to the hypervalency in the organometallic compounds of main group elements (Si, P, S) because of their high reactivities and structural interest. They are not described in this chapter, but will be discussed in Chapter 17. 

Hypervalent Compounds Silicon Organosilicon Chemistry Sulfur Inorganic Chemistry Tin Organometallic Chemistry Titanium Organometalhc Chemistry. 

Hypervalent silicon compounds 4. Reactions with organometallic reagents... 

Application of hypervalent phosphorus compounds in organometallic catalysis... 

Kayser F, Biesemans M, Gielen M and Willem R (1996) Two dimensional H- Sn proton detected correlation spectroscopy in coordination chemistry of hypervalent organotin compounds. In Gielen M, Willem R and Wrackmeyer B (eds), Advanced Applications of NMR to Organometallic Chemistry, pp 45-86. Chichester Wiley. 

Pyrylium salts, in particular, the parent compound 95, combine with organometallics under ring opening (Scheme 1-66). In contrast, thiopyrylium analogs 96, both substituted and unsubstituted ones, are reported to give hypervalent sulfabenzenes as amorphous, darkly colored solids (Scheme 1-66). ... 

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