Process for hydrogenation of halogenoalkenes without dehalogenation

A process for preparing a compound of formula VI

• wherein
• R1 and R6 is hydrogen, substituted or unsubstituted alkyl substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl;
• R5 is B(OR2)(OR3);
• wherein R2 and R3 independently from each other represent substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or substituted or unsubstituted aralkyl;
• or R2 and R3 cooperatively form a part of a 5- to 10-membered fused or unfused ring, optionally a chiral 5- to 10-membered fused or unfused ring;
• X is selected from Cl, Br, I;
• and
• * indicates a chiral center;
• by hydrogenation of a compound of formula V
• wherein R1, R5, R6 and X are as defined above;
• wherein hydrogenation is conducted in the presence of a catalyst selected from complexes comprising at least one transition metal, and said catalyst is used at a molar substrate to catalyst ratio in the range of 5:1 to 100:1, and wherein dehalogenation occurs in less than 10 molar % relative to the molar amount of the compound of formula VI.