Synthesis and evaluation of C₂-symmetric bis-sulfinamides as effective ligands in rhodium catalyzed addition of arylboronic acids to cycloalkenones

Abstract

Synthesis of novel C₂-symmetric 1,2- 1,3- and 1,4- bis-sulfinamides and their use as effective ligands in rhodium (I) catalyzed asymmetric conjugate addition of arylboronic acids to cyclohexenone and cyclopentenones is described. C₂-symmetry as well as chirality at the sulfur center in the ligand is crucial for the high enantioselectivity in the 1,4-addition reaction. It was also observed that the conjugate addition proceeded with good selectivity with Wilkinson's catalyst as the rhodium source.