Rare-earth Metal Catalyzed C-H Alkylation Of Aromatic Amines With Alkenes

The dissertation presents the synthesis of rare-earth metal dialkyl complexes based on non-cyclopentadienyl ligands,and their applications in catalytic C-H alkylation of aromatic amines with alkenes.1.Scandium(2-1)and yttrium(2-2)dialkyl complexes based on unsymmetricalβ-diketiminato ligand were synthesized,and their application in catalytic hydroaminoalkylation was studied.The hydroaminoalkylation of N,N-dimethylanilines to various extremely challenging and sterically demanding alkenes such as 1,2-disubstituted alkenes,internal alkenes and cyclic alkenes were achieved by using complex 2-1 in combination with[PhNHMe2][B(C6F5)4].Mechanism investigation demonstrated a conversion course of arene ortho-C(sp2)-H metalation to α-C(sp3)-H metalation in the mechanistic framework.2.Para-alkylation of primary and secondary anilines with a variety of sterically encumbered alkenes was achieved by using complex 2-1 in combination with[PhNHMe2][B(C6Fs)4].A series of polar functional groups such as halogen,alkoxy and dimethylamino group can be well tolerated in this catalytic system.Active species was successfully isolated and characterized by stoichiometric reaction.Controlled experiments indicate that such scandium-catalyzed hydroarylation reaction proceed with a tandem hydroamination/Hofmann-Martius rearrangement mechanism,rather than a classical Friedel-Crafts reaction mechanism.3.Scandium(4-1)and yttrium(4-2)dialkyl complexes based on anilido-oxazoline ligand were synthesized,and their application in catalytic benzylic C-H addition of aromatic amines to alkenes was studied.Using anilido-oxazoline 4-L1 as auxiliary ligand,scandium(4-1)and yttrium(4-2)dialkyl complexes were synthesized.Benzylic alkylation of aromatic amines was achieved by using complex 4-1 in combination with[PhNHMe2][B(C6Fs)4].This represents a new model for the reaction of aromatic amines with olefins.4.Rare earth complexes based on chiral arylamine-oxazoline ligand were synthesized,and their application in catalytic asymmetric alkylation of aromatic amines with olefins was studied.A series of chiral anilido-oxazoline(4-HL2,5-HL1-5-HL12)bearing versatile steric/electronic profiles were used as auxiliary ligands,and corresponding rare-earth dialkyl complexes(4-7,5-1-5-11)were synthesized.Asymmetric ortho-alkylation of aromatic amines with olefins were achieved by using complex 5-6 and[PhNHMe2][B(C6F5)4],thus a series of novel chiral aromatic amines derivatives were obtained,and their enantiomeric excess values are up to 89%.This represents the first example of asymmetric hydroarylation of aromatic amines with alkenes.The absolute configurationof the major enantiomer was determined to be S by X-ray crystallographic analysis.