Reactions of hexafluoroacetone benzenesulfonyl- and trifluoroacetylimines with arylamines

1.	Nonsterically hindered primary arylamines react with hexafluoroacetone benzenesulfonyl- and trifluoroacetylimines to give stable gem-diamino compounds.
2.	The presence of substituents at the nitrogen of the arylamine destabilizes these gem-diamino compounds, with the formation of C²- and C⁴-alkylation products. With hexafluoroacetone trifluoroacetylimine, C²-alkylation is accompanied by heterocyclization to give 1-substituted 2,4,4-tris(trifluoroacetyl)-1,4-dihydroquinazolines.
3.	N,N-Dialkylanilines are regioselectively alkylated at C⁴.