Regioselective hydroformylation of sulfonamides using a scaffolding ligand.

A highly regioselective hydroformylation of allylic sulfonamides has been developed by employing a catalytic directing group. The reaction tolerates a wide range of electronically and sterically modified olefins, and only 10% of the scaffolding ligand is required to effectively control the regioselectivity.

Catalytic scaffolding ligands: an efficient strategy for directing reactions.

The design and application of a scaffolding ligand that promotes branch and diastereoselective hydroformylation of terminal olefins as well as the regio- and diastereoselective hydroformylation of disubstituted olefins is reported. It is shown that the ligand covalently and reversibly bonds to the substrate, allowing for directed hydroformylation. As the substrate ligand interaction is dynamic, hydroformylations are catalytic in ligand and do not require any additional synthetic steps to add or remove the directing group. Using a catalytic quantity of a scaffolding ligand (20-25 mol %), excellent regioselectivity for disubstituted olefins (up to 98:2) and high branch selectivity (up to 88:12) for terminal olefins were obtained.