Sample Originator: Mark E. Light, Michael B. Hursthouse, Thomas Gelbrich, Peter N. Horton, Simon J. Coles, C. S. J. Cazin and R. B. Bedford.



Identification Number:10.5258/ecrystals/126
Date Created:27 February 2001
Deposited On:21 Jan 2008 15:29
Deposited By:A.N. Admin

Depositor Comments

A range of ortho-metalated catalysts with alkylphosphine ligands of the general formula [Pd(X)(2N,C-C6H4CH2NMe2)(PR3)] have been synthesized, and the crystal structures of five examples (R = Cy, X = TFA, OTf, Cl, I; PR3 = PCy2(o-biphenyl), X = TFA) have been determined. The crystal structures of two dimeric precursor complexes, [{Pd(-TFA)(2N,C-C6H4CH2NMe2)}2] and [{Pd(TFA)(2N,C-C6H4CH=NiPr)}2], have also been determined. The application of the phosphine adducts to both Suzuki coupling and Buchwald-Hartwig amination reactions with aryl chloride substrates was examined, and the performance of these catalysts versus conventional palladium sources was evaluated. In general the palladacyclic complexes show considerably enhanced activity. Typically, the best activity is seen with tricyclohexylphosphine adducts in Suzuki coupling and tri-tert-butylphosphine analogues in amination reactions. In nearly all the amination reactions performed, small amounts of a second product species were observed, namely 4,6-bis(aryl)-3,4-dihydro-2H-[1,4]oxazines. The crystal structure of one example, 4,6-bis(4-methoxyphenyl)-3,4-dihydro-2H-[1,4]oxazine, was determined. Studies on the activation of palladacyclic precatalysts in the coupling of morpholine led to the isolation of a morpholine adduct, [Pd(TFA)(2N,C-C6H5CH2NMe2){NH(CH2CH2)O}], which was structurally characterized by X-ray analysis.

Data collection parameters

Chemical formulaC24 H24 F6 N2 O4 Pd2
Crystal morphology
Crystal systemOrthorhombic
Space group symbolP2(1)2(1)2(1)
Cell length a11.0425(2)
Cell length b15.4028(3)
Cell length c16.0274(4)
Cell angle alpha90.00
Cell angle beta90.00
Cell angle gamma90.00
Data collection temperature150(2)

Refinement results

Solution figure of merit0.0297
R Factor (Obs)0.0296
R Factor (All)0.0343
Weighted R Factor (Obs)0.0671
Weighted R Factor (All)0.0688

Citation: Light, Mark E. and Hursthouse, Michael B. and Gelbrich, Thomas and Horton, Peter N. and Coles, Simon J. and Cazin, C. S. J. and Bedford, R. B. (2001) University of Southampton, Crystal Structure Report Archive. (doi:10.5258/ecrystals/126)
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