Metallation–substitution of an α-oxygenated chiral nitrile
作者:Madeha R. Alshawish、Graeme Barker、Nicholas D. Measom、Iain Coldham
DOI:10.1016/j.crci.2016.11.006
日期:2017.6
Deprotonation of a chiral alpha-oxygenated nitrile with the base 2,2,6,6-tetramethylpiperidylmagnesium chloride, TMPMgCl, gives rise to a chiral magnesiatednitrile, and this anion has sufficient configurationalstability at low temperature to allow the formation of highly enantiomerically enriched substituted nitrile products after electrophilic quench.
An alpha-chiral nitrile carbanion generated by deprotonation of enantioenriched O-carbamoyl cyanohydrin was trapped in situ with ethyl cyanoformate to give the corresponding ester derivative in 92% yield and 90 : 10 er, providing the first example of trapping of an alpha-chiral acyclic nitrile carbanion that has been considered to be very configurationally labile.