Sub Liste()
Dim cel As Range, ref As Range
For Each cel In Range("A3:G20").SpecialCells(xlCellTypeConstants, 2)
Set ref = Range("I65536").End(xlUp)(2)
If Application.CountIf(Range("I3", ref), cel) = 0 Then ref = cel
Next
Range("I3", ref).Sort Key1:=Range("I3"), Order1:=xlAscending, Header:=xlNo
End Sub