When did Naruto learn how to generate a Rasengan unassisted? Jiraiya, Minato, and Kakashi each could generate and maintain a Rasengan using only one hand. When Naruto first learned the technique, he needed shadow clones to help him.

When did Naruto learn how to generate and maintain a Rasengan without the aid of shadow clones or chakra arms?
The first time Naruto used Rasengan without clones is in Naruto episode 134 at around 8:20.

Edit: Here is the part where Naruto first used Rasengan with only one hand.