Angular2 http post not passing the json object to MVC 6 controller action

See more:

AngularJs

ASP.NET5

MVC6

1.Controller action

[HttpPost]
public IActionResult addNewUser(string name) //tested with [FromBody]
{
     return Json(name);
}

2.angular2 http post

--UserComponent.ts
this.userService.AddUser(name).subscribe(
            res => {
                this.toggle('list');
            }
        );

--UserService.ts        
AddUser(name: string) {
        return this.ExecutePost('addNewUser', name).map((newUser: string) => { return newUser });
    }

--BaseService.ts
protected ExecutePost(action: string, name: string) {
        let body = JSON.stringify({ name: name });
        let headers = new Headers({ 'Content-Type': 'application/json;charset=utf-8' });

        return this.http.post(this._baseUrl + action, body, { headers: headers })
            .map(res => { return res.json(); }).catch(this.handleError);
    }

I am able to access the same action with Jquery ajax and it is working fine.

$(document).ready(function () {
        $.ajax({
            method: "POST",
            url: "/Home/addNewUser",
            data: { 'name': 'cebeDev' }
        })

    });

Or, Is there anything am missing on the startup.cs file?
Startup.cs

public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
            // Set up configuration sources.
            var builder = new ConfigurationBuilder()
                .AddJsonFile("appsettings.json")
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
                .AddEnvironmentVariables();

            if (env.IsDevelopment())
            {
                // This will push telemetry data through Application Insights pipeline faster, allowing you to view results immediately.
                builder.AddApplicationInsightsSettings(developerMode: true);
            }
            Configuration = builder.Build();
        }

        public IConfigurationRoot Configuration { get; set; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // Add framework services.
            services.AddApplicationInsightsTelemetry(Configuration);

            services.AddMvc();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddConsole(Configuration.GetSection("Logging"));
            loggerFactory.AddDebug();

            app.UseApplicationInsightsRequestTelemetry();

            if (env.IsDevelopment())
            {
                app.UseBrowserLink();
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
            }

            app.UseIISPlatformHandler();

            app.UseApplicationInsightsExceptionTelemetry();

            app.UseStaticFiles();

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Home}/{action=Index}/{id?}");
            });
        }

        // Entry point for the application.
        public static void Main(string[] args) => WebApplication.Run<Startup>(args);
    }

Please help.

What I have tried:

I am working on an angular 2 application using asp.net MVC6. Angular2 Http post method calls the controller action and works properly when there is no parameter/properties, but when i add a parameter to the controller action, The expected JSON mapping is not happening while trying to call action with the parameter values. Debugging the action shows null value to the parameter.