1393803-06-9Relevant academic research and scientific papers
Preparation of chiral 1,2,4-triazolium salts as new NHC precatalysts
Strand, Ragnhild B.,Solvang, Tina,Sperger, Christian A.,Fiksdahl, Anne
, p. 838 - 842 (2012/09/22)
The preparation of new chiral N,N′-disubstituted 1,2,4-triazolium based NHC salt precursors, Ia′ and Ib, from phenylhydrazine and l-phenylalanine is reported. The 1,3,4-trisubstituted triazolium salt Ia′ was obtained by a stepwise ring construction from l-phenylalanine via the corresponding imino ether and acetohydrazonamide, while a heterocyclic O-/N-heteroatom exchange strategy, based on a ring-opening/ring-closure of the oxadiazolium precursor, afforded the 1,4-disubstituted 1,2,4-triazolium salt Ib. The need for two different synthetic strategies is discussed.
