I believe the easiest way would be to formylate the indole to the indole-3-aldehyde, and then react it with nitroethane/nitropropane to get the nitroalkene, then reduce it with LAH or similar.
http://rhodium.lycaeum.org (http://rhodium.lycaeum.org)
The indoleacetaldehyde is very polymerization-prone, and I believe the imine would be too.
http://rhodium.lycaeum.org (http://rhodium.lycaeum.org)