Development of modifiable bidentate amino oxazoline directing group for Pd-catalyzed arylation of secondary C-H bonds

Abstract

Abstract A novel bidentate α-amino oxazolinyl directing group has been developed. Different from previous directing groups, this newly designed directing group was easily prepared from amino acids and modified in structure. This auxiliary preferentially effects functionalization at secondary C(sp 3)-H bonds, rather than at aryl C(sp 2)-H bonds. The diastereoselectivity of direct arylation between geminal secondary C(sp 3)-H bonds in linear molecules has also been realized for the first time with a chiral directing group by remote chirality relay. Two diastereoisomers are produced with the same chiral source by changing the substituents of substrates and aryl halides. A new direction: A multifunctional amino oxazoline directing group that is readily available from amino acids, has been developed, which can induce chemo-, regio- and diastereoselectivity in secondary C(sp 3)-H arylation reactions. Furthermore, this directing group is removable and modifiable. Steric control and counterions play important roles in the relayed chirality transfer.