Chemistry of Tertiary Carbon Center in the Formation of Congested C−O Ether Bonds

Stereoselective Construction of Tertiary Homoallyl Alcohols and Ethers by Nucleophilic Substitution at Quaternary Carbon Stereocenters

An efficient method for the stereoselective construction of tertiary C-O bonds via a stereoinvertive nucleophilic substitution at the quaternary carbon stereocenter of cyclopropyl carbinol derivatives using water, alcohols and phenols as nucleophiles has been developed. This substitution reaction proceeds under mild conditions and tolerates several functional groups, providing a new access to the stereoselective formation of highly congested tertiary homoallyl alcohols and ethers.

Stereoinvertive Nucleophilic Substitution at Quaternary Carbon Stereocenters of Cyclopropyl Ketones and Ethers

A highly regio‐ and diastereoselective nucleophilic substitution at the quaternary carbon stereocenter of cyclopropyl ketones and cyclopropyl carbinol derivatives using TMSBr, DMPSCl and TMSN₃ as nucleophiles has been developed. A variety of acyclic tertiary alkyl bromides, chlorides and azides were therefore prepared with excellent diastereopurity. The substitution occurs at the most substituted quaternary carbon center in a stereoinvertive manner, which may be attributed to the existence of a bicyclobutonium species.