Functionalization of DNA-Tagged Alkenes with Diazo Compounds via Photocatalysis.

To explore potential chemical space using DNA-encoded library (DEL) technology, the development of various types of robust DNA-compatible reactions is urgently needed. Diazo compounds, which serve as valuable building blocks and important synthons in synthetic chemistry, have been rarely applied in DEL synthesis, probably because of their potential modifications of the bases and phosphate backbone of DNA. Herein we report two cases of DNA-compatible reactions with alkenes and diazo compounds, providing corresponding hydroalkylation and cyclopropanation products in moderate to excellent yields. Notably, these transformations not only provide new access to C(sp 3 )-C(sp 3 ) bond formation in DELs with excellent functional group tolerance but also represent practical ligation methods to introduce functionalized molecules into DNA.