The first intermolecular ring-opening hydroacylation of alkylidenecyclopropanes with chelating aldehydes through a rhodium-catalyzed acrylamide-promoted protocol is reported. This highly efficient catalytic system enables the direct synthesis of a diverse range of linear γ,δ-unsaturated ketones. Good functional group compatibility is demonstrated for the completely atom-economical and remarkably selective
Osmium Models of Intermediates Involved in Catalytic Reactions of Alkylidenecyclopropanes
作者:Miguel A. Esteruelas、Ana M. López、Fernando López、José L. Mascareñas、Silvia Mozo、Enrique Oñate、Lucı́a Saya
DOI:10.1021/om400597q
日期:2013.9.9
The complex [OsCpκ3-P,C,C-PiPr2[C(CH3)═CH2]}(CH3CN)]PF6 (1) reacts with (2-pyridyl)methylenecyclopropane, at room temperature, to give initially the cyclobutylidene derivative [Os(η5-C5H5)(═CCH2CH2CH-o-C5H4N)PiPr2[C(Me)═CH2]}]PF6 (2), as a result of the ringexpansion of the alkylidenecyclopropane unit. Over time complex 2 rearranges into the cyclobutene derivative [Os(η5-C5H5)η2-C(═CHCH2CH2)-o
Formation of Osmium− and Ruthenium−Cyclobutylidene Complexes by Ring Expansion of Alkylidenecyclopropanes
作者:Ruth Castro-Rodrigo、Miguel A. Esteruelas、Sara Fuertes、Ana M. López、Fernando López、José L. Mascareñas、Silvia Mozo、Enrique Oñate、Lucía Saya、Lara Villarino
DOI:10.1021/ja904893j
日期:2009.11.4
Alkylidenecyclopropanes containing a chelation assistant at the terminal carbon atom of the olefinic moiety undergo an Os- or Ru-promoted ring expansion reaction to afford metal cyclobutylidene derivatives. The process occurs through a novel mechanism that implies a 1,2-migration of a CH(2) group of the three-membered ring from an olefinic carbon atom to the other one. It takes place, without direct
Palladium-Catalyzed Hydroalkynylation of Alkylidenecyclopropanes
作者:Lara Villarino、Fernando López、Luis Castedo、José L. Mascareñas
DOI:10.1002/chem.200901821
日期:2009.12.14
promote the addition of CH bonds of terminal alkynes (2) to alkylidenecyclopropanes (1). The reaction gives rise to 1,4‐enynes (3) in good yields. The catalytic cycle probably consists of a Pd‐catalyzed CH activation of the terminal alkyne, a regioselective hydropalladation followed by distal bond cleavage of the alkylidenecyclopropane, and a final reductive elimination.
[C^N]‐Alkenyl Gold(III) Complexes by Proximal Ring‐Opening of (2‐Pyridyl)alkylidenecyclopropanes: Mechanistic Insights
作者:Jorge A. González、Felipe Verdugo、José Luis Mascareñas、Fernando López、Cristina Nevado
DOI:10.1002/anie.202007371
日期:2020.11.2
Pyridine‐substituted alkylidenecyclopropanes (Py‐ACPs) react with gold(III) salts under mild reaction conditions through an unprecedented, proximal ring‐opening pathway, to generate highly appealing, catalytically active pyridine alkenyl [C^N]‐gold(III) species. Mechanistic studies reveal that the activation of the C−C bond of the ACP takes place through an unusual concerted, σ‐bond metathesis type‐process