Inspired by this article, except for C#: http://benjiweber.co.uk/blog/2015/08/17/lambda-parameter-names-with-reflection/

DictLiteral.cs

public IDictionary<string, TValue> Dict<TValue>(
    params Func<dynamic, TValue>[] pairs)
{
    return pairs.ToDictionary(pair => pair.Method.GetParameters()[0].Name,
                              pair => pair(null));
}

Usage.cs

void Main()
{
    // Classic way
    var d2 = new Dictionary<string, string>
    {
        {"foo", "bar"},
        {"omg", "1"}
    };

    // "Literal"
    var d = Dict(
        foo => "bar",
        omg => 1.ToString()
    );
}