Catalytic enantioselective C-H functionalization of indoles with α-diazopropionates using chiral dirhodium(II) carboxylates : asymmetric synthesis of the (+)-α-methyl-3-indolylacetic acid fragment of acremoauxin A

• Goto, Takayuki

• Natori, Yoshihiro

• Takeda, Koji

• Nambu, Hisanori

• Hashimoto, Shunichi

Abstract

An enantioselective C-H functionalization of N-methoxymethyl (MOM)-protected 2,3-unsubstituted indoles with α-diazopropionates has been effected under catalysis by dirhodium(II) tetrakis[N-phthaloyl-(S)-triethylalaninate], Rh2(S-PTTEA)4, providing α-methyl-3-indolylacetates in high yields and with enantioselectivities of up to 86% ee. The effectiveness of this protocol was demonstrated by the first catalytic asymmetric synthesis of the (+)-α-methyl-3-indolylacetic acid fragment of acremoauxin A, a potent plant-growth inhibitor. Furthermore, the Fujioka protocol using a combination of TMSOTf and 2,2'-bipyridyl was shown to be superior for the removal of the N-MOM group.

Journal

• Tetrahedron : Asymmetry

  Tetrahedron : Asymmetry 22 (8), 907-915, 2011-04-30

  Elsevier

Details

• CRID: 1050001339008450560
• NII Article ID: 120003260036
• HANDLE: 2115/46945
• ISSN: 09574166
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles