public Dictionary<string, bool> MyDic { get; set; }

MyDic = new Dictionary<string, bool>();
MyDic.Add("First", true);
MyDic.Add("Second", false);

public class MyCheck : NotifyProperty
{
  private bool _isChecked;       
  public bool IsChecked
  {
    get { return _isChecked; }
    set { _isChecked = value; OnPropertyChanged(); }
  }

  public MyCheck (bool isChecked)
  {
    IsChecked = isChecked;
  }
}


public Dictionary<string, MyCheck> MyDic { get; set; }

MyDic = new Dictionary<string, MyCheck>();
MyDic.Add("First", new MyCheck(true));
MyDic.Add("Second", new MyCheck(false));

<CheckBox IsChecked="{Binding MyObject.MyDic[Second].IsChecked}" Content="Второй"/>