Intermolecular Asymmetric Hydroamination

Significance This report describes the synthesis of 4,4′-di- tert -butyl SEGPHOS ( 1 ) and its use and comparison to SEGPHOS as well as BINAP derivatives in the intermolecular hydroamination reaction. The six-step synthesis of the ligand includes a resolution step utilizing DBTA allowing access to both enantiomers of the ligand. The Pd(OTf) 2 (NCMe) 2 / 1 complex gave the highest ee for the hydroamination of 4-F-styrene with aniline. The 4- and 4′-positions of BINAP are known to be very sensitive for the selectivity of the various asymmetric transformations. This paper describes the similar effect on SEGPHOS ligands.