3-Indolylphosphines as ligand for palladium in Suzuki–Miyaura coupling reaction of chloroarenes: substituent effects

The ligand 1,3-bis(diphenylphosphino)-1H-indole, L1 with palladium promotes Suzuki–Miyaura coupling reaction of chloroarenes and benzyl chlorides with arylboronic acids. Structural modification of L1 established that the phosphine group at C-3 position of indole was crucial to catalysis and its efficacy depended on the nature of the N-substituent. 31P chemical shift values of the substituted indolylphosphines appear to show a correlation with observed trend in catalytic efficiency.