Counterattack reagent bis(trimethylsilyl)acetamide in the disilylation of diols

The counterattack method was applied to the disilylation of diols. Treatment of various diols with 0.3 or 1.1 equivalents of potassium hydride and 1.1 equivalents of bis(trimethylsilyl)-acetamide in THF gave the corresponding disilyl ethers in good to excellent yields (60–95%). The diols may contain other functionalities, such as amide, amine, ether, and thioether. The diols used in the disilylation were 2a–14a. The newly developed disilylation proceeded in one flask by a sequential deprotonation-silylation-deprotonation-silylation pathway. This disilylation also represents an example of a “tandem double-counterattack process”. Bis(trimethylsilyl)-acetamide acted as a counterattack reagent; it provided two Me3Si groups to diols and produced amides as bases.