In the latest bits it is possible to use the dnx command prompt and PowerShell commands to do this, yes
Scaffold-DbContext '<connectionString>' EntityFramework.MicrosoftSqlServer
or
dnx ef dbcontext scaffold "<connectionString>" EntityFramework.MicrosoftSqlServer
or (from EF Core RC2)
dotnet ef dbcontext scaffold "<connectionString>" Microsoft.EntityFrameworkCore.SqlServer
You must install the Microsoft.EntityFrameworkCore.Tools
package for the command to work.