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 R4 is a hydrogen atom or a C1-6 alkyl group optionally having substituent(s), and R5 and R6 are each a C1-6 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).