IANAL, but you're describing a buy-sell agreement, which would cover what would happen to business assets in various death / divorce / firing scenarios. Often,

IANAL, but you're describing a buy-sell agreement, which would cover what would happen to business assets in various death / divorce / firing scenarios. Often, you would agree to sell your assets back to the company in the event that you no longer have direct involvement with the company. If the assets pass to her through divorce, the agreement would still bind the shares, so he doesn't technically need a nuptial agreement for this.