No there is not. A type alias in C# must be a closed (aka fully resolved) type so open generics are not supported
This is covered in section 9.4.1 of the C# Language spec.
Using aliases can name a closed constructed type, but cannot name an unbound generic type declaration without supplying type arguments.
namespace N2
{
using W = N1.A; // Error, cannot name unbound generic type
using X = N1.A.B; // Error, cannot name unbound generic type
using Y = N1.A<int>; // Ok, can name closed constructed type
using Z<T> = N1.A<T>; // Error, using alias cannot have type parameters
}