Enantioselective catalytic remote perfluoroalkylation of α-branched enals driven by light
作者:Matteo Balletti、Tommy Wachsmuth、Antonio Di Sabato、Will C. Hartley、Paolo Melchiorre
DOI:10.1039/d3sc01347b
日期:——
Herein, we report a photochemical organocatalytic method for the asymmetric introduction of perfluoroalkyl fragments (including the valuable trifluoromethyl moiety) at the remote γ-position of α-branchedenals. The chemistry exploits the ability of extended enamines (dienamines) to form photoactive electron donor–acceptor (EDA) complexes with perfluoroalkyl iodides, which under blue light irradiation
A facile access to 2,3,6-trisubstituted2H-pyran-5-carboxylates is developed by employing 2-alkyl-2-enals as reactants with acetoacetates. The reaction involves Knoevenagel condensation followed by a 6π-electrocyclization, in which the presence of the C2 alkyl substituent in the enals favors the formation of (E)-Knoevenagel adducts for the ensuing electrocyclization. The resulting 2H-pyrans are hydrogenated