According to the Mirror, the Red Devils are closing in on a £35m ($48m) deal for Sanchez, who currently has six months left on his current Gunners deal.
Jose Mourinho's side is reported to have offered the Chilean a £400,000-per-week deal ($549,600) along with a £30m ($41m) sign-on fee as well as huge agent fees.
With a transfer to Old Trafford imminent, under-pressure Arsenal boss Arsene Wenger is now to set to splurge the cash as he hopes for a strong second half of the season.
The Mirror report claims United midfielder Mkhitaryan is set to be a part of the Sanchez deal, with Wenger being a big admirer of the former Dortmund man before his move to Manchester. The Armenian's valuation is yet to be agreed but the Red Devils are understood to be "desperate" to complete a deal.
Brazilian winger Malcom is set to join the club as well as the Bordeaux man is likely to complete a £35m deal this week.
Ideally being brought in as a replacement for Sanchez, the 20-year-old could feature in his last game for the Ligue 1 club on Tuesday, 16 January, against Caen before finalising his move to the Emirates Stadium.
Meanwhile, Borussia Dortmund's Aubameyang has also emerged as a recent target for the north London club. The Gabon international is being monitored by Arsenal as he recently landed himself in trouble for missing a crucial team meeting on Saturday, 13 January.
As a result, he was not named in Dortmund's squad for their 0-0 draw against Wolfsburg on Sunday, 14 January, with club director Michael Zorc later revealing that he was not happy with the forward who was not "focused". The 28-year-old is expected to cost a steep €60m (£53m, $73m).