public string WorkspaceConnectionString {get; set;}

await QueuedTask.Run(() =>
{
  Map map = MapView.Active.Map;
  Geodatabase geodatabase = new Geodatabase(new DatabaseConnectionFile(new Uri(@"C:\Connections\mySDE.sde")));
  CIMSqlQueryDataConnection sqldc = new CIMSqlQueryDataConnection()
  {
    WorkspaceConnectionString = geodatabase.GetConnectionString(),
    GeometryType = esriGeometryType.esriGeometryPolygon,
    OIDFields = "OBJECTID",
    Srid = "102008",
    SqlQuery = "select * from MySDE.dbo.STATES",
    Dataset = "States"
  };
  var lcp = new LayerCreationParams(sqldc)
  {
    Name = "States"
  };
  FeatureLayer flyr = LayerFactory.Instance.CreateLayer<FeatureLayer>(lcp, map);
});