2022 Volume 80 Issue 12 Pages 1100-1112
Organic azides are well-known for the synthetic organic reactions by their energetic characteristics and the click functionality connecting two components. Especially in click chemistry, the azido groups as 1,3-dipolar play a key role in chemical biology. On the other hand, azido groups can also work as nucleophiles possessing diazonium leaving groups and as electrophiles, but the low reactivity has avoided their use. Herein, we disclose our synthetic achievements in the non-1,3-dipolar use of organic azides. As nucleophiles, the organic azides with allyl/propargyl cations and sulfonium ions gave the appropriate products, including C-C bond migration. We also demonstrated that the intramolecular hydrogen bonding interaction promoted the electrophilicity and suppressed the nucleophilicity of the azides to achieve site-selective conjugation. Furthermore, β-elimination followed by condensation converted the azido groups at the carbonyl α-position to the different click functional groups. This site-selective azido group conversion enabled the undistinguishable triazide molecule to the distinguishable triple-click scaffold compound possessing three different click groups.
