Does the Maxima have an atomatic shutdown for engine overheating?

I am not aware of any emergency shut down. When you get a major leak the problem is that the temperature sensor will not be in the coolant anymore as it is higher in the cooling circuit. So, the temperature you get on the gauge is only ambient and not the real engine temprature. So, you could have been operating in the red zone. Even if it was not knocking or struggling you could have some damage. I would suggest a compression test. You can get the tool to do one at any Advance Auto or Auto Zone on a loaner basis.

Nissan do have a system whereby the engine would shut down when it overheats but quite often the system kicks in too late, meaning damage had been done.

However there is no reset system. Most probably you have damaged the engine or some sensors due to the overheating and if the compression test is low, try pumping some engine oil into the spark hole and cranking the engine for the oil to lubricate the rings and retest the compression. If the compression increases to within specs, you can try starting. If it still fails to start, check for trouble codes.
Overheating can damage sensors.