Diphosphine ligand and transition metal complex using the same
The present invention provides a novel ligand represented by the following formula and a novel transition metal complex having the ligand, which shows superior enantioselectivity and catalytic efficiency, particularly high catalyst activity, in various asymmetric synthesis reactions. A transition metal complex having, as a ligand, a compound represented by the formula wherein R 4 is a hydrogen atom or a C 1-6 alkyl group optionally having substituent(s), and R 5 and R 6 are each a C 1-6 alkyl group optionally having substituent(s), or the formula is a group represented by the formula wherein ring B is a 3- to 8-membered ring optionally having substituent(s).
1. A compound represented by the formula
wherein:
R 4a is a C 1-6 alkyl group optionally having substituent(s), and R 5a and R 6a are each a C 1-6 alkyl group optionally having substituent(s), or
R 4a is a hydrogen atom or a C 1-6 alkyl group optionally having substituent(s), and the formula
is a group represented by the formula
wherein ring B′ is a 3- to 8-membered ring optionally having substituent(s), or a salt thereof.
2. The compound of claim 1 , wherein R 4a , R 5a and R 6a are each a C 1-6 alkyl group optionally having substituent(s).
3. The compound of claim 1 , wherein R 4a is a hydrogen atom or a C 1-6 alkyl group optionally having substituent(s), and the formula
is a group represented by the formula
wherein ring B′ is a 3- to 8-membered ring optionally having substituent(s).