B. McDermott, A. Campbell, A. Ertan
Apr 1, 2008
Citations
0
Influential Citations
29
Citations
Journal
Synlett
Abstract
This paper describes the first known example of a (-)-sparteine-mediated asymmetric deprotonation of a piperazine. Reaction of TERT-butyl 4- TERT-butylpiperazine-1-carboxylate with S-BuLi in the presence of (-)-sparteine at -78 °C and quenching with carbon dioxide proceeded in good yield and with a high degree of selectivity (er = 89:11). X-ray crystal structure analysis on a chiral derivative confirmed the R-enantiomer was the major product. This methodology was employed as a route to an advanced chiral intermediate that was used in parallel synthesis of a range of molecules of medicinal interest. Optimisation of the chemistry used to introduce a TERT-butyl group onto a piperazine nitrogen is also described.