Creating a list of KeyValuePair:

Dictionary<int, int> dictionary = new Dictionary<int, int>();
List<KeyValuePair<int, int>> list = new List<KeyValuePair<int, int>>();
list.AddRange(dictionary);

Creating a list of keys:

Dictionary<int, int> dictionary = new Dictionary<int, int>();
List<int> list = new List<int>();
list.AddRange(dictionary.Keys);

Creating a list of values:

Dictionary<int, int> dictionary = new Dictionary<int, int>();
List<int> list = new List<int>();
list.AddRange(dictionary.Values);