List KeyValuePair

List<KeyValuePair<string,string>> list = new List<KeyValuePair<string, string>>();

list.Add(new KeyValuePair<string, string>("asdf1", "1"));

list.Add(new KeyValuePair<string, string>("asdf1", "1"));

list.Add(new KeyValuePair<string, string>("asdf1", "1"));

Dictionary<string, string> dictionary = list.ToDictionary(x => x.Key, x => x.Value);

list = dictionary.ToList();