Efficient catalytic synthesis of optically pure 1,2-azido alcohols through enantioselective epoxide ring opening with HN3

Chiral binuclear Co(salen) complexes bearing Lewis acid of group 13 metal chlorides show very high catalytic activity and enantioselectivity for the ring opening of epoxides using HN3 as azide source. It provides a facile and practical synthetic route to a wide range of chiral nonracemic 1,2-azido alcohols and related compounds in one-pot synthesis with excellent selectivity (92.0–99.6% e.e.) under mild conditions. The presence of Lewis acid of group 13 shows a strong synergistic effect.

Inactive Co(salen) complexes are easily activated by the Lewis acid of group 13 metal chlorides as a result of formation of heterometallic complexes. These complexes show very high catalytic activity for the asymmetric ring opening of epoxides with HN3. Figure optionsDownload as PowerPoint slide