Finding chiral carbons in aromatic or cyclic compounds I know that for a carbon to be chiral four different groups should be attached to that particular carbon. But, what about in the case of cyclic compounds? What's the method to check chirality if the carbon is not $\mathrm{sp}^3$ hybridized and only three, or two groups are attached to it (through double or triple bonds)?
If an atom is part of a double or a triple bond it is never a stereogenic center because then this atom and the atoms bound to it form something planar, so that you can always find a symmetry plane.
But an atom that is part of a double bond can be prochiral, if it can be converted from to a stereogenic center in a single step.