A set of novel aromatic and heteroaromatic bench‐stable sulfoxide‐based boronates was prepared. The structure of the boronates was established by means of X‐ray crystallography, and the prepared boronates were successively used in Suzuki cross‐coupling reactions under different conditions. We also developed a tandem Suzuki reaction so that a base is generated during the nucleophilic addition of Grignard reagents to 4‐bromobenzaldehyde. The formed intermediates were smoothly coupled with the prepared boronates and the boronic acids under external base‐free conditions.