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Synlett 2004(12): 2103-2106  
DOI: 10.1055/s-2004-831304
LETTER
© Georg Thieme Verlag Stuttgart · New York

Preparation of New N-Heterocyclic Carbene Metal-Alkyne Complexes and Application to a Stereocontrolled Pauson-Khand Reaction

Andrew M. Poultona, Steven D. R. Christie*a, Ross Fryatta, Sophie H. Dalea, Mark R. J. Elsegooda, David M. Andrewsb,
a Deptartment of Chemistry, Loughborough University, Loughborough, LE11 3TU, UK
Fax: +44(1509)223925; e-Mail: s.d.christie@lboro.ac.uk;
b Metabolic and Viral Chemistry, GlaxoSmithKline, Stevenage, SG1 2NY, UK
Further Information

Publication History

Received 3 June 2004
Publication Date:
26 August 2004 (online)

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Abstract

The first reported bimetallic metal-alkyne complexes containing a singly bonded N-heterocyclic carbene ligand have been synthesised and utilised in a stereocontrolled Pauson-Khand reaction.

Key words

alkyne compexes - carbene complexes - asymmetric synthesis

1

Current address: AstraZeneca, Alderley Park, Macclesfield, Cheshire, SK10 4TF, UK

18

Determination of the absolute stereochemistry of the IPr substituted complexes and the cyclopentenones is under investigation and will be reported in due course.

19

We thank the referees for their suggestions for the mechanism of the epimerisation.

20

Crystal data for 4d: C36H40Co2N2O6, M = 714.56, monoclinic, a = 10.5677(5), b = 17.9251(8), c = 19.7400(8) Å, β = 103.980(2) ° U = 3628.5(3) Å3, T = 150 K, space group P21/c (no. 14), Z = 4, µ(MoKα) = 0.958 mm-1, 30948 reflections measured, 8656 unique (R int = 0.017) which were used in all calculations. The final wR2(F 2) = 0.0925 (all data), R1 = 0.0342 [for 7200 data with F 2>2σ(F 2)]. The Co2 core of the molecule was modelled as disordered with the Co atoms having minor disorder components with an occupancy factor of 8.4(2)%. Crystallographic data have been deposited with the Cambridge Crystallographic Data Centre (CCDC 229596).