There might be some very strange or edgy 'naruto and sasuke kill sakura fanfic' in the depths of the internet. But it goes against the essence of the characters. Naruto is all about protecting his friends and Sasuke, while he has his dark moments, still has a connection to Sakura. This kind of fanfic could be a result of someone wanting to shock the readers or explore a really twisted 'what - if' scenario that has no basis in the normal Naruto storyline.
In the Naruto fandom, such a fanfic would be very out of character for both Naruto and Sasuke. They are comrades and friends with Sakura. However, some dark or AU (Alternate Universe) fanfics might explore extreme and unorthodox ideas. But in the main canon, they would never do this as they have a deep bond with Sakura. Naruto has been friends with her since childhood and Sasuke, despite his aloofness, also values her in his own way.