4982-35-8Relevant academic research and scientific papers
Synthesis of a Tetraphenyl-Substituted Dihydropentalene and Its Alkali Metal Hydropentalenide and Pentalenide Complexes
Boyt, Stuart M.,Hintermair, Ulrich,Jenek, Niko A.,Kociok-K?hn, Gabriele,Sanderson, Hugh J.
, (2021/11/17)
We report a high-yielding solution phase synthesis of 1,3,4,6-tetraphenyl-dihydropentalene based on a simple annulation reaction of cyclopentadiene with a chalcone. Deprotonative metalation of 1,3,4,6-tetraphenyl-dihydropentalene with alkali metal bases (
Divergent ring-opening coupling between cyclopropanols and alkynes under cobalt catalysis
Yang, Junfeng,Shen, Yixiao,Lim, Yang Jie,Yoshikai, Naohiko
, p. 6928 - 6934 (2018/09/11)
Cobalt-diphosphine catalysts promote ring-opening coupling reactions between cyclopropanols and unactivated internal alkynes, affording either β-alkenyl ketones or multisubstituted cyclopentenol derivatives in good yields with good to excellent regioselectivities. The chemoselectivity between these β-alkenylation and [3 + 2] annulation reactions, which likely share a cobalt homoenolate as a key catalytic intermediate, is exquisitely controlled by the reaction conditions, with the solvent being a major controlling factor. The reactions are proposed to involve ring opening of cobalt cyclopropoxide into homoenolate, migratory insertion of the alkyne into the Co-C bond, and protodemetalation or intramolecular carbonyl addition of the resulting alkenylcobalt species. The feasibility of these reaction steps was supported by DFT calculations.
Regioselective synthesis of trisubstituted cyclopentadienyl ligands from furans
Csák?, Aurelio G.,Contreras, Claudia,Mba, Myriam,Plumet, Joaquín
, p. 1451 - 1454 (2007/10/03)
1,2,3- And 1,2,4-trisubstituted cyclopentadienyl manganese tricarbonyl compounds have been synthesized regioselectively from furans following a common synthetic strategy. The key steps include the transformation of furylcarbinols into hydroxycyclopentenones followed by the conjugate addition of Grignard reagents under chelation directed conditions. This affords hydroxycyclopentanones which can be dehydrated to cyclopentenones. These compounds are further elaborated into the final targets by the 1,2-addition of organolithium reagents.
Metal-catalyzed cyclopropene rearrangements for benzannulation: Evaluation of an anthraquinone synthesis pathway and reevaluation of the parallel approach via carbene-chromium complexes
Semmelhack,Ho, Suzzy,Cohen,Steigerwald,Lee,Lee,Gilbert, Adam M.,Wutff, William D.,Ball, Richard G.
, p. 7108 - 7122 (2007/10/02)
The reaction of 3-arylcyclopropenes with Cr(CO)6 and Mo(CO)6 produces naphthols, in an example of metal-promoted benzannulation. Substituents at C- 3 (in addition to aryl) have a strong effect on the success of the process: 3-H deriv
Transition-metal-promoted ring-opening reactions of vinylcyclopropenes. 1,2,3,5-η-Penta-2,4-dienediyl and 1,5-η-penta-2,4-dienediyl (1-metallacyclohexa-2,4-diene) complexes of rhodium(III) and iridium(III) and their conversion to (η5-cyclopentadienyl)hydridometal compounds
Egan Jr., James W.,Hughes, Russell P.,Rheingold, Arnold L.
, p. 1578 - 1581 (2008/10/08)
1,2,3-Triphenyl-3-vinyl-1-cyclopropene (2) reacts with "MCI(PMe3)2" (M = Rh, Ir) to give novel complexes 3a,b containing the 1,2,3,5-η-penta-2,4-dienediyl ligand, one of which, the iridium species 3b, has been crystallographically characterized. In contrast, reaction of 2 with the bulkier reagent "RhCl(P-i-Pr3)2" yields directly the (cyclopentadienyl)hydridorhodium complex 6. Reaction of 3a with (acetylacetonato)thallium affords the (1,5-η-penta-2,4-dienediyl)rhodium (1-rhodacyclohexa-2,4-diene) complex 8 which has also been crystallographically characterized.
Photochemical Studies of Cyclopropenes and Cyclopentadienes. Mechanistic and Exploratory Organic Photochemistry
Zimmerman, H. E.,Kreil, D.J.
, p. 2060 - 2075 (2007/10/02)
The photochemistry of two vinylcyclopropenes and one cyclopentadiene was investigated.Thus, 3-phenyl-3-(1-phenylvinyl)cyclopropene, 3-phenyl-3-(2,2-diphenylvinyl)cyclopropene, and 2,5,5-triphenylcyclopentadiene were studied.The vinylcyclopropenes were designed with the vinyl moieties being the low-energy chromophores in contrast to previously studied examples where the cyclopropene ? bond is lower in energy.As with previous vinylcyclopropenes, irradiation led to cyclopentadienes and indenes. 2,5,5-Triphenylcyclopentadiene was the main photoproduct of the irradiation of the (diphenylvinyl)cyclopropene. 3-(2,2-Diphenylvinyl)indene was a lesser product that was encountered. 1,2-Diphenylcyclopentadiene, 3-(1-phenylvinyl)indene, and 3,4-diphenyl-1,2,4-pentatriene were formed from direct photolysis of the styryl cyclopropene.Interestingly, the corresponding sensitized irradiation led exclusively to 1,2-diphenylcyclopentadiene.Quantum efficiencies were determined for these reactions.Direct irradiation of 2,5,5-triphenylcyclopentadiene led to novel ring contraction to afford the (diphenylvinyl)cyclopropene.Additionally, phenyl migration was observed, leading to formation of 1,4,5-triphenylcyclopentadiene.Sensitized reaction of 2,5,5-triphenylcyclopentadiene led only to the phenyl migration product.Again quantum yields were determined.The (diphenylvinyl)cyclopropene was labeled in order to ascertain the skeletal change in the rearrangement.Similary, labeling studies were carried out with 2,5,5-triphenylcyclopentadiene, thus allowing delineation of the fate of each carbon.Additionally, studies were carried out independently to generate the 3,5,5-triphenylpentadienyl carbene.The (diphenylvinyl)cyclopropene was the major product along with 2,5,5-triphenylcyclopentadiene and 3-(2,2-diphenylvinyl)indene.
