according to the invention corresponds to formula (II) below:in which,M represents a metal such as ruthenium, rhodium or iridium;X represents a halogen such as chlorine, bromine, fluorine or iodine;Sv represents a tertiary amine, a ketone, an ether;L represents a (R) or (S) chiral diphosphine of formula (I) above;y is a whole number equal to 0 or 1;x is a whole number equal to 1 or 2;z is a whole