Redirect to an action from Application_BeginRequest in global.asax

All above will not work you will be in the loop of executing the method Application_BeginRequest.

You need to use

HttpContext.Current.RewritePath("Home/About");

Use the below code for redirection

   Response.RedirectToRoute("Default");

"Default" is route name. If you want to redirect to any action,just create a route and use that route name .