Method for preparing borinic acid derivatives and novel borinic acid derivatives

A borinic acid derivative of general formula (2′):

• (Ar′2B(OH) (2′)
• wherein Ar′ represents a group of the following formula:
• wherein m represents 0 or 1, A represents —O—, —S— or —NR1—, A may further represent —C(R2)2— in the case where m is 0, R1 represents a hydrogen atom, alkyl group having 1 to 6 carbon atoms or aromatic cyclic hydrocarbon group, and R2 may be the same or different and represents a hydrogen atom or alkyl group having 1 to 6 carbon atoms;
• R represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms, and n represents 0 to 5;
• a formula:
• represents a single bond or double bond, that is to say a ring that contains A may therefore be saturated or unsaturated;
• and
• a symbol:
• * indicates the bonding site to B (boron) provided that the substitution positions of R and the symbol:
• * are respectively not limited to a benzene ring.

A method for preparing a borate salt of general formula (4):

• wherein Ar represents an aromatic cyclic hydrocarbon group or aromatic heterocyclic group, M′ represents Li+ or Mg2+, p is 1 in the case where M′ is Li+, and p is 2 in the case M′ is Mg2+,
• comprising reacting a compound of general formula (1):
• Ar-M (1)
• wherein Ar is the same as previously defined, M represents Li or MgX, and X represents a chlorine atom, bromine atom or iodine atom,
• with tri-t-butyl borate.

A borate salt of general formula (5):

• wherein Ar′ represents a group of the following formula:
• wherein m represents 0 or 1, A represents —O—, —S— or —NR1—, A may further represent —C(R2)2— in the case where m is 0, R1 represents a hydrogen atom, alkyl group having 1 to 6 carbon atoms or aromatic cyclic hydrocarbon group, and R2 may be the same or different and represents a hydrogen atom or alkyl group having 1 to 6 carbon atoms;
• R represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms, and n represents 0 to 5;
• a formula:
• represents a single bond or double bond, that is to say a ring that contains A may therefore be saturated or unsaturated;
• and
• a symbol:
• * indicates the bonding site to B (boron) provided that the substitution positions of R and the symbol:
• * are respectively not limited to a benzene ring;
• and
• M′ represents Li+ or Mg2+, p′ is 1 in the case where M′ is Li+, and p′ is 2 in the case where M′ is Mg2+.