The structural and electronic effects produced by several gold atoms embedded into sulfur vacancies of molybdenum disulfide monolayers are assessed theoretically for the first time. These MoS2 defects need less formation energies, of about 3 eV per sulfur vacancy, than those found for other commonly studied bidimensional systems. The defects introduce several new states, mostly from the molybdenum d orbitals, in the band gap. The gap is reduced by means of the sulfur vacancies; which are lowered up to 0.570 eV for the tri-sulfur vacancies. Previously, the inert MoS2 monolayer is activated through sulfur vacancies, which becomes able to trap gold atoms. The gold clusters occupying sulfur sites are energetically favorable, as shown by the estimated binding energies, higher than - 2.4 eV per atom. These defects create states in the band gap, which arise from the molybdenum and gold orbitals, gradually reducing the energy up to 0.450 eV. Moreover, the Au atoms receive charges from Mo atoms; being able to transfer it towards other species. That is, the gold atoms may define the catalytic site of the MoS2 monolayer. In fact, those embedded atoms could be suitable for nucleophilic as well as electrophilic attacks according to Fukui indices. Embedded clusters enhanced the reactivity of the whole material which is suggested to act as a catalyst, due to the properties found on it.