using System;

using System.Collections.Generic;

using System.Linq;

using Newtonsoft.Json;

using Newtonsoft.Json.Serialization;

​

public class Program

{

    public class Item

    {

        [JsonIgnore]

        public string Name { get; set; }

        public string Prop1 { get; set; }

    }

    public static void Main()

    {

​

        var items = new List<Item>

        {

            new Item { Name = "a", Prop1 = "123" },

            new Item { Name = "b", Prop1 = "456" },

            new Item { Name = "c", Prop1 = "789" }

        };

        var obj = items.ToDictionary(x=> x.Name, x => x);

        var json = JsonConvert.SerializeObject(obj, new JsonSerializerSettings 

        { 

            ContractResolver = new CamelCasePropertyNamesContractResolver() 

        });

        Console.WriteLine(json);

    }

}