Page 271 - Arrow Pushing in Inorganic Chemistry A Logical Approach to the Chemistry of the Main Group Elements

FURTHER READING 251
7. Many higher-valent p-block oxides, broadly defined, effect oxygen atom transfers to
lower-valent p-block compounds. DFT calculations in the authors’ laboratory sug-
gest that the mechanisms are best viewed as direct S 2-like displacements and do
N
not involve oxo-bridged intermediates.
8. Sulfur tetrafluoride and aminosulfur trifluorides are important fluorinating agents
that typically operate via a non-redox mechanism. Similarly, Martin sulfurane is a
tetravalent sulfur-based dehydrating agent for alcohols, which also operates via a
non-redox pathway.
9. Sulfonium ions and cationic tetravalent sulfur centers stabilize adjacent anions. Sul-
foxides, in the form we have depicted them in this chapter, are good examples of
such stabilization, as are sulfur nitrides such as S N and S N . Sulfonium ylides
2
2
4
4
provide yet another example of the phenomenon.
10. Although sulfur and phosphorus ylides attack carbonyl compounds in the same way
initially, the reaction pathways subsequently diverge. The tetravalent sulfur center
typically undergoes reductive elimination, producing DMS and an epoxide (the JCC
reaction, Section 6.10). In the case of phosphorus ylides, the pentavalent phosphorus
center remains pentavalent and ends up as a highly stable phosphine oxide (the Wittig
reaction, Section 5.9b), while the carbonyl group ends up as an alkene.

FURTHER READING

1. Devillanova, F. A., ed. Handbook Of Chalcogen Chemistry: New Perspectives in Sulfur, Selenium
and Tellurium; Royal Society, 2006. 740 pp. An excellent source for newer aspects of chalcogen
chemistry that are not yet adequately covered in standard textbooks.
2. Chivers, T. A Guide To Chalcogen-nitrogen Chemistry; World Scientific: Singapore, 2004. 318 pp.
A full treatment of a fascinating class of compounds.
3. Furukawa, N.; Sato, S. “New Aspects of Hypervalent Organosulfur Compounds,” Topp. Curr.
Chem. 1999, 205, 89–129.