Simple Synthesis of Amides and Weinreb Amides via Use of PPh3or Polymer-Supported PPh3and Iodine.
The combination of PPh3/I2has been shown to be effective for conversion of a range of carboxylic acids to 2°, 3°, and Weinreb amides. Simplification of the procedure was possible with the use of polymer-supported PPh3/I2. Weinreb amides produced via the use of polymer-supported PPh3could be filtered through a short silica gel plug and used in further transformations. Thus, use of polymer-supported PPh3offers potential applicability to diversity-oriented reactions. Formal total syntheses of apocynin and pratosine, as well as syntheses of anhydrolychorinone and hippadine, have been achieved via the use of this amide-forming method. An attempt has been made to gain insight into this reaction.
Department of Chemistry, The City College and The City University of New York, 160 Convent Avenue, New York, NY 10031-9198, U.S.A.
Amit
A
Kumar
Hari Kiran
HK
Akula
Mahesh K
MK
Lakshman
Amide; Weinreb amide; iodine; polymer-supported triphenylphosphane; triphenylphosphane