Missing out on the Brazilian is a fresh blow for Arsene Wenger, who has missed out on several targets this summer, and is currently caught up in the saga involving Liverpool's want-away striker Luis Suarez.
Bernard, 20, signs for the Ukranian side on a five-year deal, for a fee of £21.5million (€25m) and will be aiming to fill the void left by fellow Brazilian Fernandinho's move to Manchester City earlier this summer.
Missed out: Bernard was impressive in Atletico Mineiro's Copa Libertadores win, and has five caps for Brazil
The move comes as a surprise as it was thought that the youngster, who can play behind the striker or on the wing, was favouring a move to Portugal, being persuaded by Brazil teammate and former Porto player Hulk.
Speaking to O Jogo, Bernard's father said: 'Hulk has convinced Bernard that Porto would be better for him at this stage of his career.
'Porto would be a better move for his career. It would be a dream of mine to see him playing for them.'
Arsenal were also vying for his signature, especially after the departure of Gervinho to Roma has left a shortage of wingers at the north London club.
More transfer problems: Luis Suarez has been forced to train alone (at Melwood with daughter above) after expressing his desire to leave LiverpoolWenger meanwhile, has said that the move for Uruguayan stiker is 'on standby' after the 26-year-old told his club he wanted to play Champions League football.
Reds boss Brendan Rodgers has criticised the striker for showing a complete 'lack of respect' and has ordered him to train by himself for the time being.
