A series of asymmetrical substituted tetrahydropyrimidinium salts and different kinds of bridged bis-tetrahydropyrimidinium salts were prepared through the quaterization of tetrahydropyrimidine or the dehydrogenation of hexahydropyrimidine. They were characterized and used as NHC precursors in the palladium catalyzed Buchwald--Hartwig amination reaction. The in situ formed catalytic system Pd(OAc)_2/tetrahydropyrimidinium and ^tBuOK catalyzed the amination of heteroaryl halides and heterocyclic amines effectively, producing the heterocyclic amine functionalized heteroaryl derivatives in high yields.
YANG, LIANGRU; BIAN, HUANYU; MAI, WENPENG; MAO, PU; XIAO, YONGMEI; WEI, DONG; and QU, LINGBO
"Synthesis of tetrahydropyrimidinium salts and their in situ catalytic activities towards the Buchwald--Hartwig amination reaction under microwave irradiation,"
Turkish Journal of Chemistry: Vol. 39:
1, Article 11.
Available at: https://journals.tubitak.gov.tr/chem/vol39/iss1/11