SPANphos
Chemical compound
SPANphos is an organophosphorus compound used as a ligand in organometallic and coordination chemistry. The compound is a rare example of a trans-spanning ligand and rigidly links mutually trans coordination sites. By virtue of its C2-symmetric backbone, SPANphos forms a chiral cavity over the face of a square planar complexes, e.g. in MCl2(SPANphos) (M = Pd, Pt).
01Synthesis
SPANphos can be prepared synthesized from relatively inexpensive reagents. In the first step 4,4,4',4',6,6'-hexamethyl-2,2'-spirobichromane is prepared via an acid-catalyzed reaction of p-cresol and acetone. The resultant spirocycle is halogenated with N-bromosuccinimide followed by lithium-bromide exchange using n-BuLi. Treatment of the resulting dilithio compound with chlorodiphenylphosphine completes the synthesis.
Sources and credits
This article is adapted from the Wikipedia article “SPANphos”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- SPANphos.svg by Hbf878, Public domain
- WABXIH.png by Smokefoot, CC BY-SA 4.0
- SPANphosPrep.png by Smokefoot, Public domain
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