Rhodium-catalyzed [2+2+2] cycloaddition of various fluorine-containing alkynes--novel synthesis of multi-substituted fluoroalkylated aromatic compounds.
Treatment of various fluorinated internal alkynes with 10 mol% of RhCl(3).H(2)O and 30 mol% of i-Pr(2)NEt in toluene at the reflux temperature for 18 h gave the corresponding trimerization products as an isomeric mixture in high yields. Cycloaddition using 1.0 equiv. of fluorinated alkynes and 2.0 equiv. of non-fluorinated alkynes under the same reaction conditions as in the trimerization led to mono- and bis-fluoroalkylated benzene derivatives in high yields, together with small amounts of trimerization products. The reaction of fluorine-containing bispropargyl ether with non-fluorinated alkynes took place smoothly to afford the corresponding bicyclic molecules in good to high yields.
Department of Chemistry and Materials Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan. konno@chem.kit.ac.jp
Tsutomu
T
Konno
Kazuki
K
Moriyasu
Ryoko
R
Kinugawa
Takashi
T
Ishihara
D000480:Alkynes / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D017611:Fluorine Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D006841:Hydrocarbons, Aromatic / Q000138:chemical synthesis* / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry*
D000480:Alkynes; D017611:Fluorine Compounds; D006841:Hydrocarbons, Aromatic; D012238:Rhodium