One-Pot Negishi Coupling of Alkyl Bromides with Hetaryl Halides

Significance

The methodology, described in this work, offers an easy route to polysubstituted amino-heteroarenes, starting from the corresponding hetaryl chlorides and alkylzinc halides, or benzyl or phenethyl bromides and diethylzinc. The halogen-zinc exchange reaction and Ni-catalyzed cross-coupling can be performed in ‘one pot’ in the last case. The amino group does not interfere in the process, provided it is blocked by the excess of alkylzinc reagent. This is one of the first reports of a Negishi coupling of alkylzinc derivatives with heteroaryl halides. This method is quite convenient for the synthesis of alkylsubstituted hetero­arenes. The reaction can be scaled up to at least 100 mmol.