using System;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        var contentJson = "[[{Prop1: 1, Prop2: \"B\"}]]";

        var parsedArr = Newtonsoft.Json.JsonConvert.DeserializeObject<Item[][]>(contentJson);

        var parsed = parsedArr[0][0];

        Console.WriteLine("Parsed " + parsed.Prop1 + parsed.Prop2);

    }

}

​

public class Item {

    public int Prop1 {get;set;}

    public string Prop2 {get;set;}

}