using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string myString="abc {string 1} def {string 2}{string 3}";

​

        string[] result = myString.Split('{')

            .Where(x => x.Contains("}"))

            .Select(x=>new string(x.TakeWhile(c=>c!='}').ToArray()))

            .ToArray();

        foreach(var item in result)

        {

            Console.WriteLine(item);

        }

    }

}