Auxiliary-assisted palladium-catalyzed arylation and alkylation of sp2 and sp3 carbon-hydrogen bonds.
We have developed a method for auxiliary-directed, palladium-catalyzed beta-arylation and alkylation of sp(3) and sp(2) C-H bonds in carboxylic acid derivatives. The method employs a carboxylic acid 2-methylthioaniline- or 8-aminoquinoline amide substrate, aryl or alkyl iodide coupling partner, palladium acetate catalyst, and an inorganic base. By employing 2-methylthioaniline auxiliary, selective monoarylation of primary sp(3) C-H bonds can be achieved. If arylation of secondary sp(3) C-H bonds is desired, 8-aminoquinoline auxiliary may be used. For alkylation of sp(3) and sp(2) C-H bonds, 8-aminoquinoline auxiliary affords the best results. Some functional group tolerance is observed and amino- and hydroxy-acid derivatives can be functionalized. Preliminary mechanistic studies have been performed. A palladacycle intermediate has been isolated, characterized by X-ray crystallography, and its reactions have been studied.
Shabashov
Dmitry
D
Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA.
Daugulis
Olafs
O
D000478:Alkylation; D000634:Aminoquinolines / Q000737:chemistry; D000814:Aniline Compounds / Q000737:chemistry; D001596:Benzylamines / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*
D000634:Aminoquinolines; D000814:Aniline Compounds; D001596:Benzylamines; D009942:Organometallic Compounds; D010165:Palladium; D002244:Carbon; D006859:Hydrogen; C030796:benzylamine; C023650:aniline; C080436:8-aminoquinoline