Copper‐Catalyzed Borylation of Cyclic Sulfamidates: Access to Enantiomerically Pure (β‐and γ‐Amino­alkyl)boronic Esters

Cyclic sulfamidates undergo borylation under copper‐catalyzed conditions using B(2)pin(2) to give enantiomerically (and diasteromerically) defined (aminoalkyl)boronic esters. External iodide is essential, but the intermediacy of simple alkyl iodides has been excluded; N‐sulfated intermediates are key in the borylation sequence. Based on stereochemical studies and trapping experiments, the involvement of carbon‐centered radicals under these copper‐catalyzed conditions appears likely.