Can you put a reverse gear on 2001 1100 shadow bike

take the plugs out and press down on the foot starter crank lever/pedal

Yes, there IS a clutch safety switch.

http://www.bikebandit.com/houseofmotorcycles/2005-honda-shadow-aero-750-vt750c-handle-switch/o/m151126sch409843

Item #8

It could be the clutch needs adjustment or the reverse syncro is not there or needs to be replaced. good luck.

check the switch on the side stand, the bike is designed so as it cuts off if you select a gear with the stand down,

Check you side stand safety switch. If it is unplugged, removed, or malfuntioning, the bike's system will think the side stand is down and kill the engine when the bike is put into gear.

When you say you put bike in reverse gear, are you twisting the reverse gear switch? is the bike in neutral? and are you operating the engine start switch to make the bike go in reverse? This machine operates in reverse by using the starter motor.

Your kickstand switch is either broken or out of position. The bike kills the engine as a safety feature if it thinks the sidestand is down and the bike is put in gear while the engine is running.

The kickstand switch is either bad or bent out of position. See if you can activate the switch manually. Does the bike run now? If so, the switch is bent out of position. If it still won't run, jumper the wires together until you can replace the switch.

hello and welcome
it seems that you may have a faulty side stand switch. the side stand needs to be in the up position before the bike can be started off in gear. but if not the side stand contains a saftety switch that shuts the bike off when put into gear. to verify this you can check for spark when the bike is being turned over in gear with the clutch held in.
there should be two wires associated with this switch. a green, and green with white. so when the stand is up these two wires are connected, and the switch can be tested as such. thank you.