Rodl, Christian and Malberg, Jennifer Bissmeyer Nee and Wolf, Robert (2018) Functionalization of 1,3-diphosphacyclobutadiene cobalt complexes via Si-P bond insertion. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES, 73 (11). pp. 895-909. ISSN 0932-0776, 1865-7117
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We report the synthesis of functionalized 1,3-bis(diphosphacyclobutadiene) complexes via the insertion of carbon-oxygen bonds of ethers, esters, aldehydes and amides into the P-Si bond of silylated complexes. Reactions of [K(tol)(2)][Co(eta(4)-P2C2R2)(2)] [[K(tol)(2)] [1a]: R= tBu, [K(tol)(2)][1b]: R= tPent (=tert-pentyl)] with Me3SiCl afford the trimethylsilyl-substituted derivatives [Co(eta(4)-P2C2R2 SiMe3)(eta(4)-P2C2R2)] (2a,b, R= tBu, tPent). The Me3Si group is connected to a phosphorus atom of one of the 1,3-diphosphacyclobutadiene ligands. 2a,b readily react with organic substrates containing C-O single and C=O double bonds at ambient temperature. [Co(eta(4)-P2C2R2(CH2)(4)OSiMe3)(eta(4)-P2C2R2)] (3a, b) are formed by reaction of 2a, b with traces of THF. They can also be isolated by reacting the THE solvates [K(thf)(2){Co(P(2)C(2)tBu(2))(2)}] ([K(thf)(2)][1a]) and [K(thf)(3){Co(P-2 C(2)tPent(2))(2)}] ([K(thf)(3)][1b]) with Me3SiCl in toluene or THE The adamantyl-substituted complex [Co(eta(4)-P2C2R2(CH2)(4)OSiMe3)(eta(4)-P(2)C(2)Ad(2))] (3c) was prepared analogously from [K(thf)(4){Co(P(2)C(2)Ad(2))(2)}] and Me3SiCl. [K(thf)(2)][1a] reacts cleanly with Ph3SnCl affording [Co(eta(4)-P(2)C(2)tBu(2)SnPh(3))(eta(4)-P2C2Bu2)] (4) in high yield. Reaction of 2a with styrene oxide affords [Co(eta(4)-P(2)C(2)tBu(2)PhC(2)H(3)OSiMe(3))(eta(4)-P(2)C(2)tBu(2))] (5) as a single regioisomer. By contrast, multinuclear NMR spectroscopic studies indicate mixtures of two isomeric insertion products 6/6' and 7/7', respectively, which result from the insertion of 1,2-epoxy-2-methylpropane and 1,2-epoxyoctane.Moreover, these monitoring studies show that reactions of 2a with acyclic ethers afford alkyl substituted complexes such as [Co(eta(4)-P(2)C(2)tBu(2)Et)(eta(4)-P(2)C(2)tBu(2) )] (8) and alkylsilyl ethers. Reaction of 2a with y-butyrolactone gives [Co(eta(4)-P(2)C(2)tBu(2)(CH2)(3)C(O)OSiMe3)(eta(4)-P(2)C(2)tBu(2))] (9) via cleavage of the endocyclic C-O single bond of the lactone. Benzaldehyde and acetone cleanly react with 2a to [Co(eta(4)-P(2)C(2)tBu(2)CH(Ph)OSiMe3)(eta(4)-P(2)C(2)tBu(2))] (10) and [Co(eta(4)-P(2)C(2)tBu(2)CMe(2)OSiMe(3))(eta(4)-P(2)C(2)tBu(2))] (11), while the sterically more demanding ketones 3-pentanone and acetophenone selectively yield the known hydride complex [Co(eta(4)-P(2)C(2)tBu(2))(2)H] (A). Phenyl isocyanate reacts with 2a at elevated temperature to form [Co(eta(4)-P(2)C(2)tBu(2)CON(Ph) SiMe3)(eta(4)-P(2)C(2)tBu(2))] (12) with a functionalizecl eta(3) coordinated ligand. [K(tol)(2)][1a], [K(tol)(2)][1b], 2a, 2b, 3a-c, 4, 5, and 9-12 were isolated and characterized by multinuclear NMR spectroscopy, UV/Vis spectroscopy and elemental analysis. [K(tol)(2)][1b], 2a, 2b, 3c, 4, 5, and 9-12 were additionally characterized by X-ray crystallography.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | PHOSPHORUS-COMPOUNDS; MOLECULAR-STRUCTURE; ORGANOMETALLIC COMPOUNDS; UNUSUAL COORDINATION; CRYSTAL-STRUCTURES; RING CONTRACTION; METAL-COMPLEXES; 1ST EXAMPLE; PHOSPHAALKYNES; CYCLODIMERIZATION; cobalt; phosphorus; sandwich complexes; silicon |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Anorganische Chemie > Arbeitskreis Prof. Dr. Robert Wolf |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 10 Oct 2019 10:06 |
| Last Modified: | 10 Oct 2019 10:06 |
| URI: | https://pred.uni-regensburg.de/id/eprint/13641 |
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