Paul doesnt even allude to them, .....no one expects him to rehash the life and times of Jesus Christ in every letter written, that is not the point.
Paul seems to have gotten his info on visonary trips including one to heaven (2 Cor 12) and his information seems very lacking in comparison to the gospel accounts. There should have been a rich seam of information about jesus for him there and yet he mentions barely anything at all.
The logical conclusion is that the gospels were created (fabricated is a better word) later.