Is zakat obligatory on shares of a building that have not yet been sold due to a legal dispute, knowing that their owners do not currently possess the money to pay zakat? And is it permissible to pay zakat for all years after the dispute is resolved and the shares are sold?

This company is not permissible according to the majority of scholars. It must be rectified by the landowner selling a portion of the land, such as half, to his partner. Then they can proceed with building and selling, and the profit will be shared between them according to their agreement or the proportion of capital. As for zakat (definition), the husband owes zakat on the money he deposited in the bank. He is not required to pay it immediately every year; rather, he should wait until the judiciary rules on the matter and his share becomes clear and he has liquidity. Then he should pay zakat for all the past years.