Cross-Electrophile Coupling of Challenging 5-Membered Heteroaryl Bromides with Alkyl Electrophiles

High Resolution Image Download MS PowerPoint Slide Although alkylated 5-membered heteroarenes are common in pharmaceuticals, there are limited methods to construct them by cross- electrophile coupling. In this report, a systematic study of 5-membered heteroaryl bromides sheds light on an unappreciated reason for this challenge: their relative reactivity spans almost three orders of magnitude and includes examples in the range of aryl iodides and aryl chlorides. By taking this reactivity into consideration, successful conditions were found using PyBCam CN for primary alkyl halides and 4,4'-MeO Bpy complexes for secondary alkyl halides (42 examples, 60% average yield).