A General Method for Synthesis of Unclosed Cryptands via H-Bond Templated Macrocyclization and Subsequent Mild Postfunctionalization

作者:Dabrowa Kajetan; Niedbala Patryk; Majdecki Maciej; Duszewski Piotr; Jurczak Janusz*
来源:Organic Letters, 2015, 17(19): 4774-4777.
DOI:10.1021/acs.orglett.5b02324

摘要

A practical four-step synthesis of a model 26-membered N-Boc-protected macrocycle, starting from commercially available and inexpensive materials, is reported. The crucial macrocyclization step does not require high-dilution conditions and is completed in a short time (8 h). The high yield of macrocyclization (61%) is achieved owing to templation by intramolecular H-bonds and a chloride anion, which both help to adopt a favorable folded conformation of the open-chain intermediate. Finally, mild, selective, and efficient incorporation of intraannular amide function leading to five diversely functionalized unclosed cryptands (UCs) is described.

  • 出版日期2015-10-2