Switching the Chemoselectivity in the Amination of 4-Chloroquinazolines with Aminopyrazoles
摘要:
The chemoselectivity in the amination of 4-chloroquinazolines with 3-amino-1-pyrazoles was studied. Under the conditions of Pd-2(dba)(3)/Xantphos/Na2CO3, 4-chloroquinazolines underwent selective amination with the cyclic secondary amino group of 3-amino-1H-pyrazoles, whereas 4-chloroquinazolines were exclusively aminated with the primary amino group of 3-amino-1H-pyrazoles via SNAr substitution in the presence of HCI.