using System;
using System.Linq;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		var inputText = "substring1 delim+1 substring2 delim+2 substr3";
		var  delimeters = new List<string> { "delim+1", "delim+2" };
		var addrArr = Regex.Split(inputText, 
			string.Format(@"\s+(?={0})", string.Join("|", delimeters.Select(Regex.Escape))));
        Console.WriteLine(string.Join("\n", addrArr));
	}
}

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