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Chemistry of a novel zerovalent ruthenium π-acidic alkene complex, Ru (η (6)-1,3,5-cyclooctatriene)(η (2)-dimethyl fumarate)2.

Mitsudo TA, Ura Y, Kondo T - Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci. (2007)

Bottom Line: Complex 1 was shown to be an excellent mother complex for various zerovalent ruthenium complexes.Complex 1 reacts with amines, phosphines or water to give new zerovalent ruthenium complexes with the ligands.The resulting aqua complexes have a water ligand with an oxygen atom that is a chiral center, i.e., ruthenium complexes with a 'chiral water' ligand were prepared and fully characterized.

View Article: PubMed Central - PubMed

Affiliation: Professor Emeritus, Kyoto University.

ABSTRACT
A novel zerovalent ruthenium complex with a π-acidic ligand, Ru(η (6)-cyclooctatriene)(η (2)-dimethyl fumarate)2 (1), was prepared from Ru(η (4)-cyclooctadiene)(η (6)-cyclooctatriene) [Ru(cod)(cot)]. Complex 1 or Ru(cod)(cot) catalyzes various new carbon-carbon bond-forming reactions that include the [2 + 2] cycloaddition of alkenes and alkynes via ruthenacycles, the creation of a new hydrocarbon, pentacyclo[6.6.0.0(2,6).0(3,13).0(10,14)]tetradeca-4,11-diene [PCTD], by dimerization of 2,5-norbornadiene via C-C bond cleavage, and the codimerization of alkynes and/or alkenes. Complex 1 was shown to be an excellent mother complex for various zerovalent ruthenium complexes. Complex 1 reacts with amines, phosphines or water to give new zerovalent ruthenium complexes with the ligands. The resulting aqua complexes have a water ligand with an oxygen atom that is a chiral center, i.e., ruthenium complexes with a 'chiral water' ligand were prepared and fully characterized.

No MeSH data available.


CD spectra of 16a (c = 2.5 × 10−5 M) and 16b (c = 3.7× 10 −5 M) in CHCl3. For 16a: λmax 270 nm (Δε+45), 381 (−5). For 16b: λ 268 nm (Δε − 41), 378 (+5).
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f4-83_065: CD spectra of 16a (c = 2.5 × 10−5 M) and 16b (c = 3.7× 10 −5 M) in CHCl3. For 16a: λmax 270 nm (Δε+45), 381 (−5). For 16b: λ 268 nm (Δε − 41), 378 (+5).

Mentions: In a further study, the spontaneous resolution of rac-16, which occurred during recrystallization from chlorobenzene/pentane, enabled each enantiomer 16a and 16b to be isolated in pure form.26) The solid-state structures of 16a and 16b determined by X-ray crystallography are shown in Fig. 2; their absolute configurations were confirmed by the values of the Flack parameters, 0.00(4) for 16a and 0.03(4) for 16b, as refined by least-squares techniques. The water protons (H1, H2) could be found based on Fourier maps. As is clearly shown, the oxygen atom of H2O (O1) is bound to ruthenium, and the two hydrogen atoms are located close to the carbonyl oxygen atoms of the dmfm ligands (O2, O3). The distances of O1· · ·O2 (2.652(5) Å) and O1· · ·O3 (2.643(5) Å) for 16a and O1· · ·O2 (2.657(6) Å) and O1· · ·O3 (2.627(6) Å) for 16b reflect the existence of intramolecular hydrogen bonds, H1· · ·O2 and H2· · ·O3. The coordinative directions of the two dmfm ligands differ from each other; the dmfm ligands coordinate to ruthenium by the (re, re)-enantioface in 16a and by the (si, si)-enantioface in 16b. Thus, the water protons H1 and H2 are fixed in different chemical environments, and a chiral center is generated on O1 in each enantiomer (Fig. 3). Optical resolution of 16a and 16b by HPLC equipped with a chiral column was also successful and gave 16a in 98%ee and 16b in 92%ee. The CD spectra of these separated complexes measured in CHCl3 clearly showed their enantiomeric relationship (Fig. 4).


Chemistry of a novel zerovalent ruthenium π-acidic alkene complex, Ru (η (6)-1,3,5-cyclooctatriene)(η (2)-dimethyl fumarate)2.

Mitsudo TA, Ura Y, Kondo T - Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci. (2007)

CD spectra of 16a (c = 2.5 × 10−5 M) and 16b (c = 3.7× 10 −5 M) in CHCl3. For 16a: λmax 270 nm (Δε+45), 381 (−5). For 16b: λ 268 nm (Δε − 41), 378 (+5).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3756878&req=5

f4-83_065: CD spectra of 16a (c = 2.5 × 10−5 M) and 16b (c = 3.7× 10 −5 M) in CHCl3. For 16a: λmax 270 nm (Δε+45), 381 (−5). For 16b: λ 268 nm (Δε − 41), 378 (+5).
Mentions: In a further study, the spontaneous resolution of rac-16, which occurred during recrystallization from chlorobenzene/pentane, enabled each enantiomer 16a and 16b to be isolated in pure form.26) The solid-state structures of 16a and 16b determined by X-ray crystallography are shown in Fig. 2; their absolute configurations were confirmed by the values of the Flack parameters, 0.00(4) for 16a and 0.03(4) for 16b, as refined by least-squares techniques. The water protons (H1, H2) could be found based on Fourier maps. As is clearly shown, the oxygen atom of H2O (O1) is bound to ruthenium, and the two hydrogen atoms are located close to the carbonyl oxygen atoms of the dmfm ligands (O2, O3). The distances of O1· · ·O2 (2.652(5) Å) and O1· · ·O3 (2.643(5) Å) for 16a and O1· · ·O2 (2.657(6) Å) and O1· · ·O3 (2.627(6) Å) for 16b reflect the existence of intramolecular hydrogen bonds, H1· · ·O2 and H2· · ·O3. The coordinative directions of the two dmfm ligands differ from each other; the dmfm ligands coordinate to ruthenium by the (re, re)-enantioface in 16a and by the (si, si)-enantioface in 16b. Thus, the water protons H1 and H2 are fixed in different chemical environments, and a chiral center is generated on O1 in each enantiomer (Fig. 3). Optical resolution of 16a and 16b by HPLC equipped with a chiral column was also successful and gave 16a in 98%ee and 16b in 92%ee. The CD spectra of these separated complexes measured in CHCl3 clearly showed their enantiomeric relationship (Fig. 4).

Bottom Line: Complex 1 was shown to be an excellent mother complex for various zerovalent ruthenium complexes.Complex 1 reacts with amines, phosphines or water to give new zerovalent ruthenium complexes with the ligands.The resulting aqua complexes have a water ligand with an oxygen atom that is a chiral center, i.e., ruthenium complexes with a 'chiral water' ligand were prepared and fully characterized.

View Article: PubMed Central - PubMed

Affiliation: Professor Emeritus, Kyoto University.

ABSTRACT
A novel zerovalent ruthenium complex with a π-acidic ligand, Ru(η (6)-cyclooctatriene)(η (2)-dimethyl fumarate)2 (1), was prepared from Ru(η (4)-cyclooctadiene)(η (6)-cyclooctatriene) [Ru(cod)(cot)]. Complex 1 or Ru(cod)(cot) catalyzes various new carbon-carbon bond-forming reactions that include the [2 + 2] cycloaddition of alkenes and alkynes via ruthenacycles, the creation of a new hydrocarbon, pentacyclo[6.6.0.0(2,6).0(3,13).0(10,14)]tetradeca-4,11-diene [PCTD], by dimerization of 2,5-norbornadiene via C-C bond cleavage, and the codimerization of alkynes and/or alkenes. Complex 1 was shown to be an excellent mother complex for various zerovalent ruthenium complexes. Complex 1 reacts with amines, phosphines or water to give new zerovalent ruthenium complexes with the ligands. The resulting aqua complexes have a water ligand with an oxygen atom that is a chiral center, i.e., ruthenium complexes with a 'chiral water' ligand were prepared and fully characterized.

No MeSH data available.