The Enantioselective Ring-Opening of Six-Membered Cyclic Iodonium Salts for the Synthesis of Axially Chiral Diaryl Ethers Containing Phosphinate Moiety.

Construction of chiral compounds via the enantioselective ring opening of cyclic diaryliodonium salts represents a hot research topic in modern organic synthesis. In this work, an enantioselective ring-opening reaction of oxygen-fused six-membered cyclic diaryliodonium salts was developed. Using phosphoric acids and phosphine oxides as nucleophiles, a series of axially chiral diaryl ethers bearing a phosphinate moiety were successfully prepared. The reactions furnished the target products in moderate to good yields (up to 78%) with excellent enantioselectivity (most 99% ee). Thermal racemization studies confirmed the outstanding configurational stability of the obtained products.