Of all of the Russian oligarchs who deserve sanctions, Oleg Deripaska is at the top of the list.
https://secondnexus.com/mitch-mcconnell-deripaska-manafort-russia
In 2018, acting at the request of then National Security Advisor H.R. McMaster, who was on his way out of the Trump White House, the Treasury Department imposed sanctions on Deripaska and his aluminum company, Rusal. The company's stock tanked 50 percent on the news. The move was part of a broad set of sanctions against Russian oligarchs. As for Deripaska specifically, according to the Treasury, he had been "investigated for money laundering, and has been accused of threatening the lives of business rivals, illegally wiretapping a government official, and taking part in extortion and racketeering."
But by 2019, Trump moved to lift the sanctions and cut a deal with Deripaska, despite a key Senate Intelligence Committee report having described him as a "proxy for the Russian state and intelligence services." Outraged Democrats moved to stop the White House. But when the Senate began debating the sanctions, McConnell played a key role in persuading his GOP colleagues to back him, and together they blocked the Democratic-backed efforts. The sanctions went away.
Three months later, there was an unusual coincidence: Rusal announced a major deal to buy a 40 percent stake in a new American aluminum plantin Ashland, Kentucky, McConnell's home state. McConnell stated he was unaware of Rusal's interest in the factory at the time the sanctions bill debate was occurring, but the alarming timing of these events earned McConnell the moniker "Moscow Mitch."
As if this wasn't enough, Deripaska was also a key figure in the shady dealings of Paul Manafort, the former Trump Campaign manager who went to prison on a seven and a half year sentence and ultimately refused to cooperate with investigators, but was among those pardoned by Trump on his way out of office. Manafort once received $10 million in funds from Deripaska, who was communicating and apparently sending instructions via another character wanted by the FBI named Konstantin Kilimnik, with whom Manafort worked closely.