The Blues were this week on the brink of completing the signing of 20-year-old Genk winger De Bruyne, who they have been linked with for several months.
But manager Villas-Boas revealed on Friday afternoon the decision to fork out a reported £8million for the player had come from above.
"You have to speak to the people from the club about that," he said.
"It's club policy. It's not within my immediate projects.
"He's a player the club has scouted for some time. I'm a manager who respects club policy."
It has long been assumed Chelsea bosses have not had full control over transfers since Roman Abramovich bought the club.
The likes of Andriy Shevchenko, Alex and even Fernando Torres were all said to be Abramovich buys.
But while his predecessors have tiptoed around the subject - sometimes describing such signings as 'joint decisions' - Villas-Boas is the first to explicitly distance himself from a new arrival.
He added of De Bruyne, who is expected to be loaned back to Genk should he sign before the transfer window closes: "A club has to look to the future, whether it's with this manager or another. He's a good bet for the future."
Someone who has the potential to improve their current squad is Shakhtar Donetsk star Willian, who Chelsea had a £16.7million bid rejected for this week - according to the Ukrainian champions.
Villas-Boas ruled out resurrecting a move for the Brazilian before the transfer window closes, even if Shakhtar lower their demands.
"It's an extremely interesting player, but I don't think we'll progress with our interest," he said.
"Different issues, from work permit to price valuation. Our project next year is more important than the 'actual project' at the moment.
"We're betting a lot on what we can build on for next year."
Villas-Boas claimed Chelsea were being priced out of the January market.
He said: "Regarding the forwards, we looked at the options but the problem, in that sense, was that there are clubs asking for a lot of money and there's not a lot of money around, in society or in football clubs.
"We have to take responsibility in making correct market judgements and buying accordingly.
"We have to understand that the January market is extra inflated. You have to take that into account."
Villas-Boas denied Chelsea were looking to sell Jose Bosingwa, insisting they still planned to activate a clause in the right-back's contract that would keep him at the club until 2014.
But he did unequivocally rule the Blues out of the Premier League title race, with the gap to leaders Manchester City now 13 points.
"It's absolutely impossible in the Premier League," he said, admitting he had long written off the championship.
"The distance is massive and we don't expect this record-breaking leader to lose points.
"We have to find the consistency to get the best position in the league possible.
"The FA Cup and the Champions League, they're trophies we will try to win and hope to win."
Defeat at QPR on Saturday would end Chelsea's involvement in the former competition but Villas-Boas played down the consequences of such a result.
He added: "It's one of the most prestigious trophies around, and the second most important domestic trophy - the one with the biggest tradition.
"We want to go as far as we can and try to win the trophy."
With Frank Lampard injured and also a doubt for Tuesday's league game at Swansea, Michael Essien could make his first start of the season.
Villas-Boas confirmed Gary Cahill would also make his debut, probably from the bench, while there could be other changes with the midweek match in mind.
