A solid-phase iridium-based ortho-exchange catalyst for the one-step labelling of aromatic substrates with deuterium

Tetrahedron Letters

Volumn 45, Issue 47, 2004, Pages 8621-8623

  Hickey, Michael J ^a   Jones, John R ^b   Kingston, Lee P ^a   Lockley, William J S ^b   Mather, Andrew N ^a   Wilkinson, David J ^a  

^a ASTRAZENECA   (United Kingdom)

^b UNIVERSITY OF SURREY   (United Kingdom)

Author keywords

CH activation; Crabtree's catalyst; Cycloocta 1,5 dienyliridium(I); Deuteration; Isotope exchange; ortho Labelling; Polystyrene; Solid phase catalyst; Triphenylphosphine

Indexed keywords

AROMATIC COMPOUND; DEUTERIUM; IRIDIUM;

ARTICLE; ATMOSPHERE; CATALYST; CHEMICAL REACTION; EVAPORATION; FILTRATION; ISOLATION PROCEDURE; SOLID; TEMPERATURE;

EID: 7044224661     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2004.09.159     Document Type: Article

References (19)

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14. Preparation of polymer catalyst 1. (1,5-Cyclooctadiene)(pyridine) (tricyclohexylphosphine)iridium(I) hexafluorophosphate (Crabtree's catalyst, 144 mg) was dissolved in dichloromethane (9 ml) and the resulting solution added to the polymer-bound triphenylphosphine (Aldrich item 3645, nominal 3 mmol of P per gram of resin, 60 mg). The reaction flask was then capped, flushed thoroughly with nitrogen and stirred for 2 h at ambient temperature. The orange supernatant was then decanted from the deep-red polymer and the polymer washed five times by resuspension and stirring in dichloromethane (4 ml each time). The supernatant was clear and colourless after the second wash. After drying to constant weight under vacuum a blood-red solid was obtained (89.3 mg). The catalyst showed no loss of activity when stored for 10 weeks under nitrogen at -20°C. Only around 30% of the activity remained after the same period when stored in air at room temperature
15. Polystyrene-based 'Polymer-bound' triphenylphosphine is available from many suppliers. During the course of these studies active catalysts were successfully prepared from Aldrich items 3645, 36,645-5, Fluka item 93093, Argonaut item 800378 and Jandagel (Aldrich item 53,341-6)
16. 4ON requires 202.116 amu. The atom% deuterium abundance from MS was 93% (calculated for four positions). A single recrystallisation from water gave large crystal plates, mp. 164-165°C (unlabelled mp 162-164°C)
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