Patent ID: 6855848

Claim:
A process for preparing boronic acid esters by reaction of a diene with sodium borohydride in the presence of a first oxidant selected from the group consisting of an alkyl halide, a dialkyl sulfate, and mixtures thereof to form the corresponding bis(allyl)borane of the formula (I): wherein R 1 -R 6 are H, aryl or substituted or unsubstituted C 1 -C 4 -alkyl or two of the radicals R 1 -R 6 may be closed to form a cyclic system, and further reaction of the borane (I) with an alkene (II) or alkyne (IV) to: give the alkylbis(allyl)borane (III) or alkenylbis(allyl)borane (V): wherein the radicals R 7 to R 12 are: aryl, substituted or unsubstituted, alkyl-(C 1 -C 8 ), which may be branched and/or substituted, alkoxy-(C 1 -C 8 ), acyloxy-C 1 -C 8 ), O-phenyl, fluorine, chlorine, NO 2 , NH 2 , NHalkyl-(C 1 -C 8 ), Nalkyl 2 -C 1 -C 8 ), CN, CHO, SO 3 H, SO 3 R, SO 2 NH 2 , SO 2 N(alkyl-(C 1 -C 8 )) 2 , SO 2 -alkyl-(C 1 -C 8 ), COO-alkyl-(C 1 -C 8 ), CONH 2 , CO-alkyl-(C 1 -C 8 ), NHCHO, CF 3 , 5-membered heteroaryl or 6-membered heteroaryl, where two or radicals R 7 to R 12 may also form a cyclic ring system which may contain heteroatoms and directly oxidizing the alkylbis(allyl)borane (III) or alkenylbis(allyl)borane (V) In the presence of a second oxidant to form the corresponding bisallyl alkylboronate or alkenylboronate.