A Simple Aliphatic Diamine Auxiliary for Palladium-Catalyzed Arylation of Unactivated β-C(sp3)-H Bonds

Palladium-catalyzed beta-C(sp(3))-H arylation of aliphatic acid derivatives was achieved by means of 2-dimethylaminoethylamine auxiliary as a directing group. The beta-C(sp(3))-H arylation reactions with aryl and heteroaryl iodides efficiently afforded the corresponding arylated hydrocinnamic acid derivatives. Direct beta-C(sp(3))-H alkynylation, and arene C-H arylation and alkynylation were also realized under the same or slightly modified conditions. The aliphatic diamine auxiliary in the products could be readily removed by methanol in the presence of BF3 center dot OEt2. In comparison with the widely used bidentate nitrogen-containing directing groups, 2-dimethylaminoethylamine is a simple, cheap, readily available and removable, and atom-economical directing group for C-H functionalization.