Rhodium(III)-Catalyzed Addition of Indoles with Boc-Imines via C−H Bond Activation

Abstract

A rhodium-catalyzed alkylation reaction of indoles with N-Boc-imines has been developed via C−H activation to afford a series of substituted 2-indolyl-methanamine derivatives with good functional group tolerance and regioselectivity. A wide range of indole-based alkylation products could be obtained in up to 95% yield.

Indole‐N‐Carboxylic Acids and Indole‐N‐Carboxamides in Organic Synthesis

“…By using 5 mol % [Cp*RhCl 2 ] 2 and 20 mol % AgSbF 6 at 85 °C, 1,2‐dichloroethane as solvent, indole‐ N ‐carboxamides 94 and N ‐sulfonylaldimines 95 could deliver 2‐aminomethyl indole derivatives 96 in moderate yields. In 2018, Wang and coworkers established a similar reaction, in which N ‐Boc‐aldimines replace N ‐sulfonylaldimines and the corresponding products could be obtained in higher yields at lower temperature (Scheme ) …”

“…In 2018, Wang and coworkers established a similar reaction, in which N-Boc-aldimines replace N-sulfonylaldimines and the corresponding products could be obtained in higher yields at lower temperature (Scheme 24). [34] In 2018, the Ji group successfully reported a C2 allylation of indoles and allyl alcohols under the directing effect of Ncarbamoyl and catalysis of Ru or Rh (Scheme 25). [35] In this reaction, indole-N-carboxamides 97 and allyl alcohol compounds 98 could undergo a CÀ H activation process to obtain 2allky indoles 99 in mild conditions by the catalysis of RuCl 2 (pcymene)] 2 or [Cp*RhCl 2 ] 2 .…”