A series of carbene ruthenium-porphyrins [ Ru ( por )(: CR 1 R 2)] ( por = TPP ; R 1 = R 2 = p- C 6 H 4 Cl 2, p- C 6 H 4 Me 3, p- C 6 H 4 Ph 4; R 1 = Ph , R 2 = p- C 6 H 4 Ph 6; R 1 = Ph , R 2 = COPh 7; R 1 = p- C 6 H 4 Me , R 2 = CO (p- C 6 H 4 Me ) 8; R 1 = COMe, R 2 = COPh 9; por = TTP ; R 1 = R2 = Ph 1', COPh 5') were synthesized and characterized. The starting material [ Ru ( por )( CO )] was treated with corresponding diazo compounds N 2 CR 1 R 2 in CH 2 Cl 2 or octane for the diaryl carbene complexes 1', 2-4 and 6, while it was subjected to photolysis in THF , followed by reflux with the diazo compounds for the acyl carbene complexes 5' and 7-9. The compounds were robust in octane under reflux and were able to catalyze cyclopropanation reactions with methyl diazoacetate (MDA) toward a wide variety of alkenes. Monocyclopropanation of 25 alkenes was demonstrated with catalyst 3 in octane under reflux. By reaction with more than equimolar amounts of MDA in the presence of catalyst 9, the first porphyrin-catalyzed biscyclopropanation was attained toward nonconjugated α, ω-dienes, viz. 1,5-hexadiene and 1,7-octadiene.
In the two ruthenium(II)-porphyrin-carbene complexes (dibenzoylcarbenyl-kappaC)(pyridine-kappaN)(5,10,15,20-tetra-p-tolylporphyrinato-kappa(4)N)ruthenium(II), [Ru(C(15)H(10)O(2))(C(5)H(5)N)(C(48)H(36)N(4))], (I), and (pyridine-kappaN)(5,10,15,20-tetra-p-tolylporphyrinato-kappa(4)N)[bis(3-trifluoromethylphenyl)carbenyl-kappaC]ruthenium(II), [Ru(C(15)H(8)F(6))(C(5)H(5)N)(C(48)H(36)N(4))], (II), the pyridine ligand coordinates to the octahedral Ru atom trans with respect to the carbene ligand. The C(carbene)-Ru-N(pyridine) bonds in (I) coincide with a crystallographic twofold axis. The Ru-C bond lengths of 1.877 (8) and 1.868 (3) A in (I) and (II), respectively, are slightly longer than those of other ruthenium(II)-porphyrin-carbene complexes, owing to the trans influence of the pyridine ligands.
The stable title trifluoromethyl-substituted carbenyl metalloporphyrin, [Ru(C(15)H(8)F(6))(C(48)H(36)N(4))], has a five-coordinate Ru atom which is displaced from the porphyrin N(4) plane towards the axial carbene ligand by 0.230 (3) A. The Ru--C(carbene) bond coincides with a crystallographic twofold axis and its length of 1.841 (6) A is notably shorter than the value of 1.868 (3) A in the pyridine adduct.
Key indicators: single-crystal X-ray study; T = 296 K; mean (C-C) = 0.004 Å; R factor = 0.031; wR factor = 0.078; data-to-parameter ratio = 16.5.In the title compound, [Ru(C 44 H 28 N 4 )(C 8 H 5 F 3 )], the fluorinated alkylidene group is bound to a five-coordinate Ru atom, which is located toward the carbene C atom, 0.3301 (5)Å from the least-squares plane of the C 20 N 4 porphyrin core. The Ru C bond is tilted slightly from the normal to the C 20 N 4 least-squares plane due to steric repulsion between the porphyrinate ligand and the bulky trifluoromethyl group. The Ru C bond length of 1.838 (2) Å is comparable with those in bis(subsituted phenyl)carbene analogs.
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Data collectionRigaku AFC-7R diffractometer Absorption correction: none 9374 measured reflections 8916 independent reflections 7578 reflections with I > 2(I) R int = 0.017 3 standard reflections every 150 reflections intensity decay: 3.5%
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