An efficient and convenient C(sp3)H phosphorylation has been achieved via the DDQ-promoted cross-dehydrogenative coupling between cycloheptatriene and P(O)H compounds at room temperature. This transformation provides a direct synthetic route to the construction of C(sp3)P bonds with good functional group compatibility, leading to the formation of cyclohepta-2,4,6-trien-1-ylphosphonates in up to 99%