title: 3,3-Diethyl-and 3,3-dibenzyl-1,2-diferrocenylcyclopropenes.
abstract: Reactions of 2,3-diferrocenylcyclopropenone 1 with ethyl- and benzylmagnesium chlorides afford 3,3-diethyl-and 3,3-dibenzyl- 1,2-diferrocenylcyclopropenes 2 and 3, respectively, and products of nucleophilic opening of the three-membered ring resulting from the addition of RMgCl to the carbonyl group, viz., saturated ketones(4,5-diferrocenylheptan-3-ones 4a,b and 3,4-diferrocenyl-1,5-diphenylpentan-2-ones 5a,b as ca. 3: 1 mixtures of two diastereomers) and other products. The spatial structures of compounds 2 and 4a were established by X-ray diffraction analysis of single crystals. Protonation of the cyclopropenes 2 and 3 with tetrafluoroboric acid at -40 degrees C yields the corresponding 3,3-dialkyl-1 ,2-diferrocenylcyclopropylium tetrafluoroborates. Transformation of the latter into diferrocenylallylic cations upon increasing the temperature to 20 degrees C and their eprotonation under the action of N,N-dimethylaniline were studied. Electrochemical investigation of 1 and 2 shows that in both complexes the cyclopropene spacer allows electronic communication between the two outer ferrocenyl groups, this being notably greater for 2 than for 1.
authors.affiliation: Universidad Nacional Autónoma de México, Facultad de Química, Cd. Universitaria, Coyoacán, México DF, México.
authors.forename: Elena I
authors.initials: EI
authors.lastname: Klimova
authors.forename: Tatiana Klimova
authors.initials: TK
authors.lastname: Berestneva
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Cinquantini
authors.forename: Maddalena
authors.initials: M
authors.lastname: Corsini
authors.forename: Piero
authors.initials: P
authors.lastname: Zanello
authors.forename: Ruben A
authors.initials: RA
authors.lastname: Tuscano
authors.forename: Simón
authors.initials: S
authors.lastname: Hernández-Ortega
authors.forename: Marcos
authors.initials: M
authors.lastname: Martínez-García
mesh_terms: D018360:Crystallography, X-Ray; D003517:Cyclopentanes / Q000138:chemical synthesis* / Q000737:chemistry; D003521:Cyclopropanes / Q000138:chemical synthesis* / Q000737:chemistry; D004563:Electrochemistry; D005296:Ferrous Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods
chemical_list: C482272:3,3-dibenzyl-1,2-diferrocenylcyclopropene; C482273:3,3-diethyl-1,2-diferrocenylcyclopropene; D003517:Cyclopentanes; D003521:Cyclopropanes; D005296:Ferrous Compounds; D009942:Organometallic Compounds; D008274:Magnesium