A real estate broker claiming entitlement to an earned commission must allege that he was the procuring cause of the transaction. There must be a showing of something beyond the broker's mere creation of an amicable atmosphere or an amicable frame of mind that might have led to the ultimate transaction, but the broker need not control the transaction, and the broker need not negotiate the transaction's final terms or be present at the closing. The procuring cause standard applies equally to causes of action sounding in breach of contract and quasi contract, such as claims for quantum meruit and unjust enrichment.
LHWS LLC v. S.L. Green Realty Corp., NY Slip Op 03574 (1st Dep't June 2, 2022)