Programmable Ether Synthesis Enabled by Oxa-Matteson Reaction.

The Matteson-type reactions have received increasing interest in constructing complex organic molecules via iterative synthetic strategies; however, the current tactics are almost exclusively based on homologation of pure carbon chains. Here, we report the development of the oxa-Matteson reaction that enables sequential oxygen and carbenoid insertions into diverse alkyl- and arylboronates. It offers a distinct entry to a wide range of boron-substituted ethers. The utilities of this method are demonstrated in the preparation of various functional ethers, the asymmetric synthesis of an acetyl-CoA-carboxylase inhibitor, and the programmable construction of polyethers.