No.  You may claim a deductible expense only for the year in which you paid the expense.  You would have to recalculate the impact to your 2012 tax, not your 2016 tax.  However, it is now too late to claim any additional refund from a 2012 tax return, since the three-year deadline for claiming refunds on a 2012 federal tax return was April 18, 2016.