A method for the Buchwald-Hartwig mono-N-arylation of
aniline with methyl 2,6-dichloroisonicotinate using Pd(OAc)2, XPhos,
and t-BuONa is reported. Use of m-anisidine under the same conditions
resulted in the amidation of the methyl ester. Mono-N-arylation
of m-anisidine with 2,6-dichloro-N,N-diisopropylisonicotinamide
and 2,6-dibromo-N,N-diisopropylisonicotinamide,
however, was successfully achieved using Pd(OAc)2/XPhos/t-BuONa or Pd(OAc)2/(±)-BINAP/K2CO3,
respectively. The present study demonstrates the sensitivity of
this cross-coupling method to both the steric and electronic nature
of the coupling partners.
Buchwald-Hartwig N-arylation - Pd(0) cross-coupling - 2,6-dihaloisonicotinates
