using System;
using System.Linq;
using System.Collections.Generic;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		var Snippet = "Jack and Jill went up the (hill) to fetch some water";
		var Highlights = new string[] { "Jack", "(hill)", "to" };
		var rx = string.Format(@"(?<!\w)(?:{0})(?!\w)",
			string.Join("|", Highlights.Select(p => Regex.Escape(p))));
		var res = Regex.Replace(Snippet, rx,
     			"<span class=\"text-highlight\">$&</span>", 
     			RegexOptions.IgnoreCase);
		Console.WriteLine(res);
	}
}

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