Diphenyl diselenide

Diphenyl diselenide
Chemical structure of diphenyl diselenide
Chemical structure of diphenyl diselenide
Space-filling model
Space-filling model
Names
IUPAC name
1,1′-Diselanediyldibenzene
Other names
Phenyl diselenide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.015.256 Edit this at Wikidata
EC Number
  • 216-780-2
RTECS number
  • JM9152500
UNII
  • InChI=1S/C12H10Se2/c1-3-7-11(8-4-1)13-14-12-9-5-2-6-10-12/h1-10H checkY
    Key: YWWZCHLUQSHMCL-UHFFFAOYSA-N checkY
  • InChI=1/C12H10Se2/c1-3-7-11(8-4-1)13-14-12-9-5-2-6-10-12/h1-10H
    Key: YWWZCHLUQSHMCL-UHFFFAOYAK
  • c1ccc(cc1)[Se][Se]c2ccccc2
Properties
C12H10Se2
Molar mass 312.154 g·mol−1
Appearance Yellow crystals
Density 1.84 g/cm3
Melting point 59 to 61 °C (138 to 142 °F; 332 to 334 K)
Insoluble
Solubility in other solvents Dichloromethane, THF, hot Hexane
Structure
90° at Se[citation needed]
C2 symmetry[citation needed]
0 D
Hazards
GHS labelling:
GHS06: ToxicGHS08: Health hazardGHS09: Environmental hazard
Danger
H301, H331, H373, H410
P260, P261, P264, P270, P271, P273, P301+P310, P304+P340, P311, P314, P321, P330, P391, P403+P233, P405, P501
Related compounds
Related compounds
 Ph2S2,
C6H5SeH
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Diphenyl diselenide is the chemical compound with the formula (C6H5)2Se2, abbreviated Ph2Se2. This yellow-coloured solid is the oxidized derivative of benzeneselenol. It is used as a source of the PhSe unit in organic synthesis.

Preparation and properties

Ph2Se2 is prepared by the oxidation of benzeneselenoate, the conjugate base of benzeneselenol which is generated via the Grignard reagent:[1]

PhMgBr + Se → PhSeMgBr
2 PhSeMgBr + Br2 → Ph2Se2 + 2 MgBr2

The molecule has idealized C2-symmetry, like hydrogen peroxide and related molecules. The Se-Se bond length of 2.29 Å the C-Se-Se-C dihedral angle is 82° and the C-Se-Se angles are near 110°.[2]

Medical applications

Diphenyl diselenide alleviates methylmercury poisoning in grass carp.[3]

Reactions

A reaction characteristic of Ph2Se2 is its reduction:

Ph2Se2 + 2 Na → 2 PhSeNa

PhSeNa is a useful nucleophile used to introduce the phenylselenyl group by nucleophilic substitution of alkyl halides, alkyl sulfonates (mesylates or tosylates) and epoxides. The example below was taken from a synthesis of morphine.[4]

Another characteristic reaction is chlorination:

Ph2Se2 + Cl2 → 2 PhSeCl

PhSeCl is a powerful electrophile, used to introduce PhSe groups by reaction with a variety of nucleophiles, including enolates, enol silyl ethers, Grignard reagents, organolithium reagents, alkenes and amines. In the sequence below (early steps in the synthesis of Strychnofoline), a PhSe group is introduced by reaction of a lactam enolate with PhSeCl.[5] This sequence is a powerful method for the conversion of carbonyl compounds to their α,β-unsaturated analogs.[6]

Diphenyl diselenide itself is also a source of a weakly electrophilic PhSe group in reactions with relatively powerful nucleophiles like Grignard reagents, lithium reagents and ester enolates (but not ketone enolates or weaker nucleophiles). PhSeCl is both more reactive, and more efficient, since with Ph2Se2 half of the selenium is wasted.

Ph2Se2 + Nu− → PhSeNu + PhSe−

N-Phenylselenophthalimide (N-PSP) can be used if PhSeCl is too strong and diphenyl diselenide is too weak or wasteful.[7]

References

  1. ^ Reich, H. J.; Cohen, M. L.; Clark, P. S. (1979). "Reagents for Synthesis of Organoselenium Compounds: Diphenyl Diselenide and Benzeneselenenyl Chloride". Organic Syntheses. 59: 141; Collected Volumes, vol. 6, p. 533.
  2. ^ Marsh, R. E. (1952). "The Crystal Structure of Diphenyl Diselenide". Acta Crystallographica. 5 (4): 458–462. doi:10.1107/S0365110X52001349.
  3. ^ Baldissera, Matheus D.; Souza, Carine F.; da Silva, Aleksandro S.; Henn, Alessandra S.; Flores, Erico M. M.; Baldisserotto, Bernardo (2020). "Diphenyl diselenide dietary supplementation alleviates behavior impairment and brain damage in grass carp (Ctenopharyngodon idella) exposed to methylmercury chloride". Comparative Biochemistry and Physiology. Toxicology & Pharmacology. 229: 108674. doi:10.1016/j.cbpc.2019.108674. ISSN 1532-0456. PMID 31760078. S2CID 208274623.
  4. ^ Taber, D. F.; Neubert, T. D.; Rheingold, A. L. (2002). "Synthesis of (−)-Morphine". Journal of the American Chemical Society. 124 (42): 12416–12417. doi:10.1021/ja027882h. PMID 12381175.
  5. ^ Lerchner, A.; Carreira, E. M. (2002). "First Total Synthesis of (±)-Strychnofoline via a Highly Selective Ring-Expansion Reaction". Journal of the American Chemical Society. 124 (50): 14826–14827. doi:10.1021/ja027906k. PMID 12475306.
  6. ^ Reich, H. J.; Wollowitz, S. (1993). "Preparation of α,β-Unsaturated Carbonyl Compounds and Nitriles by Selenoxide Elimination". Organic Reactions. 44: 1–296. doi:10.1002/0471264180.or044.01. ISBN 0471264180.
  7. ^ Barrero, A. F.; Alvarez-Manzaneda, E. J.; Chahboun, R.; Corttés, M.; Armstrong, V. (1999). "Synthesis and Antitumor Activity of Puupehedione and Related Compounds". Tetrahedron. 55 (52): 15181–15208. doi:10.1016/S0040-4020(99)00992-8.