CuOTf-Catalyzed Selective Generation of 2-Aminopyrimidines from Carbodiimides and Diaryliodonium Salts by a Triple C(sp(3))-H Functionalization

The selective C(sp(3))-H bond functionalization is an ideal and atom-economical method in organic synthesis. In this work, 2-aminopyrimidines are generated from a Cu-catalyzed reaction between carbodiimides and diaryliodonium salts, by cleavage of four C(sp(3))-H, one C-N, and one C=N bonds in the carbodiimides. It is the first triple C(sp(3))-H bond functionalization neighboring a C=N bond. The selective synthesis of 2-aminopyrimidines is controlled by the amount of the diaryliodonium salts. The novel mechanism involving a C-N formation/1,5-H shift/1,7-H shift/6 pi-electrocyclic ring-closing/aromatization is well elucidated by the detection of important intermediates and DFT calculations.Natural Science Foundation of China [21572005, 21372014]; "973" program from the National Basic Research Program of China [2012CB821600]SCI(E)ARTICLE4757-7612