119071-18-0Relevant academic research and scientific papers
Stereoselective ring expansion of 3-vinyl-1-cyclopropenes to give (η5-cyclopentadienyl)ruthenium and (η4-cyclohexadienone)iron complexes. Exclusion of planar metallacyclohexadiene intermediates and relevance to the Do?tz reaction
Hughes, Russell P.,Trujillo, Hernando A.,Gauri, André J.
, p. 4319 - 4324 (2008/10/09)
trans-3-(β-Deuteriovinyl)-1,2,3-triphenyl-1-cyclopropene, 15, reacts with Fe2(CO)9 to give the 2,4-cyclohexadieneone complex 16, as a single isotopomer. The location of deuterium in the endo-position was confirmed by comparison of 1H NMR spectra of 16 with its isotopomer 10 and by conversion of both isotopomers to their bis(trimethylphosphine) derivatives 17a,b. NOE experiments on 17a show a positive interaction between the endo-H and PMe3; this resonance is missing in 17b. Similarly, 15 reacts with [Ru(C5Me5)Cl]4 or [Ru(C5Me5)(MeCN)3]+BF 4- to give only a single isotopomeric ruthenocene 9b, containing no deuterium. Formation of single isotopomers in each reaction excludes any access to a planar metallacyclohexadiene, or any species with a symmetry plane bisecting the CHD group, as an intermediate or transition state along the reaction pathway. Internally consistent mechanisms for formation of the six- and five-membered rings are proposed to account for the stereochemical features of these and related reactions. Analogies are drawn between these reactions and those pathways proposed for the synthetically useful Do?tz reaction for the synthesis of five- and six-membered organic rings.
Transition-metal-promoted activation of carbon-carbon bonds. A new synthetic route to substituted ruthenocene derivatives via ring expansion reactions of 3-vinyl-1-cyclopropenes
Hughes, Russell P.,Robinson, David J.
, p. 1015 - 1019 (2008/10/08)
A new route to substituted ruthenocenes is described. The reaction of [Ru(η5-C5H5)(η4-C 8H12)X] (C8H12 = 1,5-cyclpoctadiene; X = Cl, Br), [Ru(η5-C9H7)(η4-C 8H12)Cl] (C9H7 = indenyl), and [(Ru(η5-C5Me5)Cl}4] with substituted 3-vinyl-1-cyclopropenes (1) provides a high-yield route to a range of substituted ruthenocenes, [Ru(η5-C5H5)(η5-C 5R5)] {2, C5R5 = C5H2Ph3-1,2,3; 3, C5R5 = C5H3Ph2-1,2; 4, C5R5 = C5H2Ph2-1,2-Me-4; 5, C5R5 = C5HMePh3-1,2,3}, [Ru(η5-C5H2Ph3-1,2,3)] (6), and [Ru(η5-C5Me5)(η5-C 5H2Ph3-1,2,3)] (7). No intermediates in these reactions could be detected by 1H or 13C{1H} NMR spectroscopy. The cis-α,-β-disubstituted vinylcyclopropene 1,2,3-triphenyl-3-(cis-β-methylvmyl)-1-cyclopropene (1e) reacts more rapidly than its trans isomer 1d, but both yield the same ruthenocene derivative 5. Treatment of [Ru-(η5-C5H5)(η4-C 8H12)Cl] with K[C5H2Ph3-1,2,3] rapidly gives the expected 1,2,3-triphenylruthenocene derivative 2, while the reaction of [Ru(η5-C5H5)(η4-C 8H12)Cl] or [{Ru(η5-C5Me5)Cl}4] with 1,2,3-triphenylcyclopentadiene proceeds more slowly to yield complexes 5 and 7, respectively. [Ru(η5-C5H5)(η4-C 8H12)Cl] reacts similarly with cyclopentadiene to give [Ru(C5H5)2].
