Remarkable Configurational Stability of Magnesiated Nitriles
作者:Graeme Barker、Madeha R. Alshawish、Melanie C. Skilbeck、Iain Coldham
DOI:10.1002/anie.201303442
日期:2013.7.22
Quaternary stereocenters: Chiral α‐magnesiatednitriles can be formed by deprotonation and are configurationally stable at low temperature, even for acyclic examples. These can be trapped with electrophiles to give enantiomerically enriched quaternary substituted products (see scheme; TMP=2,2,6,6‐tetramethylpiperidine).
The stereochemistry of electrophilic substitutions of α‐nitrile metallocarbanions is probed through the deprotonation of enantioenriched α‐amino‐ and α‐oxynitriles bearing a carbamoyl or methoxycarbonyl group. The dipole‐stabilizing substituents affect the configurationalstability and reactivity of the α‐nitrile metallocarbanions and also change the steric course (retention vs. inversion).