Abstract: The present invention relates to the technical field of chiral synthesis, and specifically provides the synthesis and use of a new type of oxa-spirodiphosphine ligands. The bisphosphine ligand is prepared with oxa-spirobisphenol as a starting material after triflation, palladium catalyzed coupling with diaryl phosphine oxide, reduction of trichlorosilane, further palladium catalyzed coupling with diaryl phosphine oxide, and further reduction of trichlorosilane. The oxa-spiro compound has central chirality, and thus includes L-oxa-spirodiphosphine ligand and R-oxa-spirodiphosphine ligand. The racemic spirodiphosphine ligand is capable of being synthesized from racemic oxa-spirobisphenol as a raw material. The present invention can be used as a chiral ligand in the asymmetric hydrogenation of unsaturated carboxylic acids. The complex of the ligand with ruthenium can achieve an enantioselectivity of greater than 99% in the asymmetric hydrogenation of methyl-cinnamic acid.

Abstract: The present invention relates to the technical field of chiral synthesis, and specifically provides a new type of oxa-spirodiphosphine ligands. The bisphosphine ligand is prepared with oxa-spirobisphenol as a starting material after triflation, palladium catalyzed coupling with diaryl phosphine oxide, reduction of trichlorosilane, further palladium catalyzed coupling with diaryl phosphine oxide, and further reduction of trichlorosilane. The oxa-spiro compound has central chirality, and thus includes L-oxa-spirodiphosphine ligand and R-oxa-spirodiphosphine ligand. The racemic spirodiphosphine ligand is capable of being synthesized from racemic oxa-spirobisphenol as a raw material. The present invention can be used as a chiral ligand in the asymmetric hydrogenation of unsaturated carboxylic acids. The complex of the ligand with ruthenium can achieve an enantioselectivity of greater than 99% in the asymmetric hydrogenation of methyl-cinnamic acid.

Abstract: The present invention provides an oxa-spirodiphosphine ligand having a structure of general Formula (I) below: wherein in general Formula (I), R1, R2, R3 and R4 are the same, and are alkyl, alkoxy, aryl, aryloxy, or hydrogen, in which R1, R2, R3 and R4 may or may not form a ring, any two of them may form a ring, or a polycyclic ring may be formed between two pairs of them; R5 and R6 is alkyl, aryl, or hydrogen; and R7 and R8 is alkyl, benzyl, or aryl. The present invention also provides a method for asymmetric hydrogenation of ?,?-unsaturated carboxylic acids. A complex of the oxa-spirodiphosphine ligand with ruthenium shows excellent activity and enantioselectivity in the asymmetric hydrogenation of various ?,?-unsaturated carboxylic acids, with which a chiral carboxylic acid product can be obtained with an enantioselectivity up to 99%.

Abstract: The present invention relates to the technical field of chiral synthesis, and specifically provides a new type of oxa-spirodiphosphine ligands. The bisphosphine ligand is prepared with oxa-spirobisphenol as a starting material after triflation, palladium catalyzed coupling with diaryl phosphine oxide, reduction of trichlorosilane, further palladium catalyzed coupling with diaryl phosphine oxide, and further reduction of trichlorosilane. The oxa-spiro compound has central chirality, and thus includes L-oxa-spirodiphosphine ligand and R-oxa-spirodiphosphine ligand. The racemic spirodiphosphine ligand is capable of being synthesized from racemic oxa-spirobisphenol as a raw material. The present invention can be used as a chiral ligand in the asymmetric hydrogenation of unsaturated carboxylic adds. The complex of the ligand with ruthenium can achieve an enantioselectivity of greater than 99% in the asymmetric hydrogenation of methyl-cinnamic acid.