RT Journal Article T1 Copper-Catalyzed Defluorinative Allylboration of Allenes with Trifluoromethyl Alkenes A1 Fernández López, Israel A1 Fañanás Mastral, Martín A1 Jiménez Cristóbal, Hugo A1 Piñeiro Suárez, Martín AB An N-heterocyclic carbene/Cu-catalyzed coupling of allenes, bis(pinacolato)diboron, and trifluoromethyl alkenes is reported. The method allows access to stereodefined borylated 1,1-difluoro-1,5-dienes with high levels of selectivity. The integration of a 1,5-diene scaffold with boron and fluorine functionalities makes these products versatile building blocks for the synthesis of structurally diverse and valuable organofluorinecompounds such as gem-difluoroalkenes, difluoromethylene units, and alkenyl fluorides. Mechanistic studies and density functional theory calculations shed light on key mechanistic aspects of the catalytic process and suggest that the in situ generated LiCl is essential for the reaction by assisting the oxidative addition of the trifluoromethyl alkene to the catalytically generated allylcopper species. It is found that the polarization of the key C─F bond induced upon binding to LiCl results in a significant decrease of destabilizing Pauli repulsion, which is translated into a remarkable reduction of the activation barrier of the oxidative addition step. PB Wiley YR 2026 FD 2026-01-01 LK https://hdl.handle.net/20.500.14352/131861 UL https://hdl.handle.net/20.500.14352/131861 LA eng NO Piñeiro‐Suárez, Martín, et al. «Copper‐Catalyzed Defluorinative Allylboration of Allenes with Trifluoromethyl Alkenes». ChemistryEurope, vol. 4, n.o 1, enero de 2026, p. e202500296. DOI.org (Crossref), https://doi.org/10.1002/ceur.202500296. NO Ministerio de Ciencia, Innovación y Universidades NO Agencia Estatal de Investigación NO Consejo Europeo de Investigación NO Xunta de Galicia DS Docta Complutense RD 26 feb 2026