Selective B-O-Si bond formation was achieved in the reaction of bisboryloxide O(Bpin)(2) (pin = (OCMe2)(2))/boroxine (MeBO)(3) system with tertiary silane R3SiH in the presence of stoichiometric water and a catalytic amount of [M](CO)(5) ([M] = Mo(CO), W(CO), Fe) to give boryl silyl ethers. Moreover, this reaction can be applied to various hydrosilanes (disilyl compounds and secondary silanes) and hydrogermane. Some of the boryl silyl ethers thus formed were confirmed by X-ray analysis.