Alkylation of Dilithiated Ketonitriles

February 20, 2024

• Title:       

  Alkylation of Dilithiated Ketonitriles

• Image Source:

  Electrophile-Dependent Alkylations of Lithiated 4-Alkoxyalk-4-enenitriles

• Mark:

  Scheme 2

• Associated context:

  Conceptually, a similar topology is anticipated upon double deprotonation of oxonitriles 5  because the resulting dianion should have a similar substitution and hybridization pattern  (Scheme 2, cf. 6 with 3). Although the alkylations of oxonitriles 5 proved to be modestly diastereoselective, alkylations of analogous oxygen-substituted alk-4-enenitriles were generally  efficient and highly diastereoselective. Surveying an array of electrophiles revealed an unusual  electrophile-dependent diastereoselectivity not previously observed with lithiated nitriles while  defining conditions for selectively installing contiguous tertiary-quaternary stereocenters.