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Mechanistic Insights into the Pd II ‐Catalyzed Chemoselective N ‐Demethylation vs. Cyclometalation Reactivity Pathways in 1‐Aryl‐ N , N ‐dimethylethanamines
Author(s) -
Yap Jeanette See Leng,
Ding Yi,
Yang XiangYuan,
Wong Jonathan,
Li Yongxin,
Pullarkat Sumod A.,
Leung PakHing
Publication year - 2014
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201402547
Subject(s) - chemistry , triethylamine , amine gas treating , palladium , denticity , medicinal chemistry , catalysis , aryl , demethylation , reactivity (psychology) , bond cleavage , cleavage (geology) , stoichiometry , metal , stereochemistry , organic chemistry , alkyl , medicine , biochemistry , pathology , fracture (geology) , dna methylation , gene , engineering , gene expression , alternative medicine , geotechnical engineering
Abstract Two structurally isomeric substituted N , N ‐dimethylethanamines have been prepared. Treatment of the 2,4‐di‐ tert ‐butylphenyl isomer with Pd II ions generated the ortho ‐metalated complexes. On the other hand, treatment of the 2,5‐di‐ tert ‐butylphenyl‐substituted amine resulted in the unexpected chemoselective cleavage of one of the three N–C bonds, thus generating the corresponding secondary amine. The N ‐demethylation process could be catalyzed at room temperature by palladium(II) catalysts such as PdCl 2 or Pd(OAc) 2 . Furthermore, treatment with a stoichiometric amount of Pd II ions gave a metal complex in which both secondary amines were bound to Pd in an N ‐monodentate fashion. When triethylamine was introduced, one of the N ‐ethyl groups in NEt 3 was cleaved, and an unexpected heteroamine complex was produced. The products generated were isolated and characterized by X‐ray crystallography. Mechanistic insights into the cyclometalation and C–N cleavage observed are discussed.