You will be able to deduce that a cell near the one shown in blue must be white to break up a 2x2 black; and that only the 17-chain can reach to it. You will be able to show that there is a diagonal chain of white cells, shown with a red line, reaching from the top of the board all the way doen to that blue cell. With this, connecting the black on the left-side to the blacks on the right-side will be a strong constraint.