SPANphos
Names
Preferred IUPAC name
(4,4,4′,4′,6,6′-Hexamethyl-3,3′,4,4′-tetrahydro-2,2′-spirobi[[1]benzopyran]-8,8′-diyl)bis(diphenylphosphane)
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 814-334-7
  • InChI=1S/C47H46O2P2/c1-33-27-39-43(41(29-33)50(35-19-11-7-12-20-35)36-21-13-8-14-22-36)48-47(31-45(39,3)4)32-46(5,6)40-28-34(2)30-42(44(40)49-47)51(37-23-15-9-16-24-37)38-25-17-10-18-26-38/h7-30H,31-32H2,1-6H3
    Key: RQMTZMWXNZQOPD-UHFFFAOYSA-N
  • CC1=CC(=C2C(=C1)C(CC3(O2)CC(C4=CC(=CC(=C4O3)P(C5=CC=CC=C5)C6=CC=CC=C6)C)(C)C)(C)C)P(C7=CC=CC=C7)C8=CC=CC=C8
Properties
C47H46O2P2
Molar mass 704.814 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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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).

Structure of PtCl2(SPANphos)[1]

Synthesis

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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.[1]

Preparation of SPANphos from p-cresol

References

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  1. ^ a b Z. Freixa, M. S. Beentjes, G. D. Batema, C. B. Dieleman, G. P. F. van Strijdonck, J. N. H. Reek, P. C. J. Kamer, J. Fraanje, K. Goubitz and P. W. N. M. van Leeuwen (2003). "SPANphos: A C2-Symmetric trans-Coordinating Diphosphane Ligand". Angewandte Chemie International Edition. 42 (11): 1322–1325. doi:10.1002/anie.200390330. PMID 12645065.{{cite journal}}: CS1 maint: multiple names: authors list (link)

📚 Artikel Terkait di Wikipedia

Xantphos

trans-spanning ligand. A related bidentate ligand with a greater bite angle is spanphos. The ligand is prepared by double directed lithiation of 9,9-dimethylxanthene

Diphosphine ligands

well. This challenge has been resolved by the long but rigid diphosphine SPANphos. The bite angle of the diphosphine influences the reactivity of the metal

Buchwald–Hartwig amination

carbene ligands and ligands with wide bite angles such as Xantphos and Spanphos which also have been developed considerably.) The first generation (Pd[P(o-Tolyl)3]2)

Trans-spanning ligand

a trans-spanning ligand, with less steric bulk compared to TRANSPHOS. SPANphos is comparable to XANTPHOS but more reliably trans-spanning. Destefano,

Metal-phosphine complex

1,1'-Bis(diphenylphosphino)ferrocene, the trans spanning xantphos and spanphos. The complex dichloro(1,3-bis(diphenylphosphino)propane)nickel is useful