Spurs have been linked with summer swoops for the Internacional striker and Shakhtar Donetsk winger but Villas-Boas suggests those potential transfer will not occur.
"Leandro is a fantastic player that I know of. I went to see him in Brazil when I was doing nothing!" he told a press conference.
"He is obviously a good, good player but he is not on our prospect at the moment, because I think we are closed on what we are trying to do with the strike situation."
On Willian he added: "No. He is a player I was interested in last year, an extremely talented player. I wouldn't want to go very deep because I feel it would be disrespectful for Shakhtar, which is a club I have a good relationship with.
"In that sense the only thing I can tell you is that last year when I was at Chelsea I was interested in the player and I appreciate his qualities."
And Villas-Boas also made it clear that he doesn't want England international Defoe going anywhere before the end of August.
"I spoke to his [Defoe] agent two days ago and the conversations have been extremely productive, the player is a player I have immense confidence in," he said.
"I appreciate his qualities so I am hoping he will continue to be a Tottenham player in the future."