Synthesis of Dialkyl Ethers from Organotrifluoroborates and Acetals

The formation of ethers by C-O bond formation under harsh basic or acidic conditions is an entrenched synthetic disconnection in organic chemistry. We report a strategic alternative that involves the BF(3).OEt(2)-promoted coupling of stable, easily prepared acetals with widely available potassium aryl-, alkenyl-, and alkynyltrifluoroborates. This fast, operationally simple process offers straightforward access to dialkyl ethers, many of which would be difficult to prepare using classical methods. The use of MOM-protected alcohols and acetal-protected aldehydes enables ether formation without recourse to protecting-group manipulations or strong bases.