i) a strong ligand selected from the group consisting of tertiary phosphine having a pKa in water of not greater than about 6, a phosphite of the general formula (R1 O)(R2 O)(R3 O)P in which each of R1, R2, and R3 is an alkyl group having at least 9 carbon atoms, an aryl group or an alkaryl group, an arsine of the general formula R1 R2 R3 As in which each of R1, R2 and R3 have the aforestated mean