2.1 Katana                      :  Install-Package Microsoft.Owin.Host.SystemWeb -Version 4.0.0
2.2 WebApi                      :  Install-Package Microsoft.AspNet.WebApi -Version 5.2.6
2.3 WebApi para Owin(Katana)    :  Install-Package Microsoft.AspNet.WebApi.Owin -Version 5.2.6
2.4 Client de IdentiyServer 3/4 :  Install-Package IdentityServer3.AccessTokenValidation -Version 2.15.1

using System;
using System.Collections.Generic;
using System.IdentityModel.Tokens;
using System.Threading.Tasks;
using System.Web.Http;
using System.Web.Http.Cors;
using IdentityServer3.AccessTokenValidation;
using Microsoft.Owin;
using Microsoft.Owin.Security.Cookies;
using Owin;

[assembly: OwinStartup(typeof(WebApiNet4x.Startup))]

namespace WebApiNet4x
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            app.UseCookieAuthentication(new CookieAuthenticationOptions());
            DesactivarLaAsignacionPredeterminadaDeJwt();
            app.UseIdentityServerBearerTokenAuthentication(new IdentityServerBearerTokenAuthenticationOptions
            {
                Authority = "http://localhost:5000",
                RequiredScopes = new[] { "Api1" },
                DelayLoadMetadata = true,
            });

            var config = new HttpConfiguration();
            config.MapHttpAttributeRoutes();
            config.EnableCors(new EnableCorsAttribute("*","*", "*"));

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
                );

            app.UseWebApi(config);

        }

        private void DesactivarLaAsignacionPredeterminadaDeJwt()
        {
            JwtSecurityTokenHandler.InboundClaimTypeMap = new Dictionary<string, string>();
        }
    }
}