Iridium-Catalyzed Cycloaddition of Azides and 1-Bromoalkynes at Room Temperature
摘要:
Iridium dimer complexes were found to catalyze the [3 + 2] cycloaddition reaction of azides with bromoalkynes, yielding 1,5-disubstituted 4-bromo-1,2,3-triazoles in reasonable to excellent yields under mild conditions. The reaction offers a direct route to new 1,4,5-trisubstituted triazoles.
An immunoassay‐based method was used to screen numerous combinations of dipoles and dipolarophiles for their ability to undergo chemoselective and biocompatible [3+2] cycloaddition reactions. The approach fulfills most of the requirements of the click concept and led to the discovery of a copper‐catalyzed reaction that generates pyrazoles from sydnone and alkyne reagents.
Irreversibly formed fragment combination products of 1 with the initial peptide sequence were active and confirmed the targeting of the active site through the ethane‐1,2‐diamine isostere. Finally, structure‐assisted combination of fragment 1 with secondary fragments that target the S1 site in hit optimization yielded novel, entirely fragment‐based BACE‐1 inhibitors with up to 30‐fold improved binding affinity
Iridium dimer complexes were found to catalyze the [3 + 2] cycloaddition reaction of azides with bromoalkynes, yielding 1,5-disubstituted 4-bromo-1,2,3-triazoles in reasonable to excellent yields under mild conditions. The reaction offers a direct route to new 1,4,5-trisubstituted triazoles.