using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
    	var s = "{token1;token2;token3;...;tokenn}";
    	var pat = @"\A{(?<val>[^;]*)(?:;(?<val>[^;]*))+}\z";
    	var caps = new List<string>();
    	var result = Regex.Match(s, pat);
		if (result.Success)
        {
            caps = result.Groups["val"].Captures.Cast<Capture>().Select(t=>t.Value).ToList();
        }
 
        // DEMO
        Console.WriteLine(string.Join("\n", caps));
	}
}

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