Diarylphenoxy Aluminum Compounds

A diarylphenoxyaluminum compound obtainable by reacting a bis(diarylphenol) ligand of the formula (I)

• wherein
• Ar1, Ar2, Ar3 and Ar4 are identical or different and in each case, independently of one another, are an aryl radical having 6 to 15 carbon atoms or a heteroaryl radical having 2 to 15 carbon atoms which, optionally can in each case carry 1 to 7 identical or different substituents selected from the group of substituents C1- to C6-alkyl, C1- to C6-perfluoroalkyl, C1- to C6-alkoxy, C7- to C12-aralkyl, halogen, —SiR5aR6aR7a, substituted or unsubstituted C6- to C10-aryl, —NR8aR9a, —SR10a or —NO2,
• R1, R2, R3 and R4 are identical or different and in each case, independently of one another, are hydrogen, C1- to C6-alkyl, C1- to C6-perfluoroalkyl, C1- to C6-alkoxy, C7- to C12-aralkyl, halogen, —SiR5bR6bR7b, substituted or unsubstituted C6- to C10-aryl, —NR8bR9b, —SR10b, —NO2, and R1 or R2 and/or R3 or R4, together with A, can form a cyclic aromatic or nonaromatic cycle, and
• A is A(1), A(2) or A(3),
• A(1) is a straight-chain or branched and/or cyclic hydrocarbon radical having 1 to 25 carbon atoms which is optionally saturated or mono- or polyunsaturated and/or partially aromatic and optionally can have one or more identical or different hetero atoms selected from the group consisting of hetero atoms O, S and NR11, and/or one or more identical or different functional groups selected from the group consisting of functional groups C(O), S(O) and S(O)2, and, optionally can carry one or more identical or different substituents selected from substituents C1- to C6-alkyl, C1- to C6-perfluoroalkyl, C1- to C6-alkoxy, C1- to C10-acyloxy, C7- to C12-aralkyl, halogen, SiR5cR6cR7c, substituted or unsubstituted C6- to C10-aryl, substituted or unsubstituted C2- to C10-hetaryl, NR8cR9c, —SR10c—NO2, C1-to C12-acyl, or C1- to C10-carboxyl,
• A(2) is an aryl radical having 6 to 15 carbon atoms or a heteroaryl radical having 2 to 15 carbon atoms which, optionally can in each case carry 1 to 5 substituents, selected from the group of substituents C1- to C6-alkyl, C1- to C6-perfluoroalkyl, C1- to C6-alkoxy, C7- to C12-aralkyl, halogen, —SiR5dR6dR7d, substituted or unsubstituted C6- to C10-aryl, —NR8dR9d, SR10d or NO2,
• A(3) is a functional group or a hetero atom selected from the group consisting of —O—, —S—, —N(R11)—, —S(O)—, —C(O)—, —S(O)2—, —P(R11)—, —(R11)P(O)— and —Si(R12R13),
• wherein the radicals R5a, R6a, R7a, R8a, R9a, R10a to R5d, R6d,R7d, R8d, R9d, R10d and R11 to R13 are in each case, independently of one another, C1- to C6-alkyl, C7- to C12-aralkyl and/or substituted or unsubstituted C6- to C10-aryl, and the radicals R8a and R9a, R8b and R9b, R8c and R9c, R8d and R9d, independently of one another, can in each case together also form a cyclic hydrocarbon radical having 2 to 8 carbon atoms which can have one or more identical or different hetero atoms selected from the group consisting of O, S and NR11a and R11a can have the meanings given for R11,
• with an aluminum compound of the formula (II) or formula (III) or a mixture of compounds of the formulas (II) and (III)
• (R14)3-pAlHp (II),
• wherein
• Al is aluminum and
• R14 is a branched or unbranched alkyl radical having 1 to 5 carbon atoms and
• p is 0 or an integer from 1 to 3,
• MAlH4 (III),
• wherein
• Al is aluminum and
• M is lithium, sodium or potassium.

A method of producing isopulegol of the formula (IV)

• comprising cyclization of a citronellal of the formula (V)
• in the presence of a catalyst which is obtainable by reacting a bis(diarylphenol) ligand of the formula (I)
• wherein
• Ar1, A2, Ar3 and Ar4 are identical or different and in each case, independently of one another, are an aryl radical having 6 to 15 carbon atoms or a heteroaryl radical having 2 to 15 carbon atoms which, optionally can in each case carry 1 to 7 identical or different substituents selected from the group of substituents C1- to C6-alkyl, C1- to C6-perfluoroalkyl, C1- to C6-alkoxy, C7- to C12-aralkyl, halogen, —SiR5aR6aR7a, substituted or unsubstituted C6- to C10-aryl, —NR8aR9a, —SR10a or —NO2,
• R1, R2, R3 and R4 are identical or different and in each case, independently of one another, are hydrogen, C1- to C6-alkyl, C1- to C6-perfluoroalkyl, C1- to C6-alkoxy, C7- to C12-aralkyl, halogen, —SiR5bR6bR7b, substituted or unsubstituted C6- to C10-aryl, —NR8bR9b, —SR10b, —NO2, and R1 or R2 and/or R3 or R4, together with A, can form a cyclic aromatic or nonaromatic cycle, and
• A is A(1), A(2) or A(3),
• A(1) is a straight-chain or branched and/or cyclic hydrocarbon radical having 1 to 25 carbon atoms which is optionally saturated or mono- or polyunsaturated and/or partially aromatic and optionally can have one or more identical or different hetero atoms selected from the group consisting of hetero atoms O, S and NR11, and/or one or more identical or different functional groups selected from the group consisting of functional groups C(O), S(O) and S(O)2, and, optionally can carry one or more identical or different substituents selected from substituents C1- to C6-alkyl, C1- to C6-perfluoroalkyl, C1- to C6-alkoxy, C1- to C10-acyloxy, C7- to C12-aralkyl, halogen, —SiR5cR6cR7c, substituted or unsubstituted C6- to C10-aryl, substituted or unsubstituted C2- to C10-hetaryl, —NR8cR9c, —SR10c, —NO2, C1-to C12-acyl, or C1- to C10-carboxyl,
• A(2) is an aryl radical having 6 to 15 carbon atoms or a heteroaryl radical having 2 to 15 carbon atoms which, optionally can in each case carry 1 to 5 substituents, selected from the group of substituents C1- to C6-alkyl, C1- to C6-perfluoroalkyl, C1- to C6-alkoxy, C7- to C12-aralkyl, halogen, —SiR5dR6dR7d, substituted or unsubstituted C6- to C10-aryl, —NR8dR9d, SR10d or NO2,
• A(3) is a functional group or a hetero atom selected from the group consisting of —O—, —S—, —N(R11)—, —S(O)—, —C(O)—, —S(O)2—, —P(R11)—, —(R11)P(O)— and —Si(R12R13),
• wherein the radicals R5a, R6a, R7a, R8a, R9a, R10a to R5d, R6d, R7d, R8d, R9d, R10d and R11 to R13 are in each case, independently of one another, C1- to C6-alkyl, C7- to C12-aralkyl and/or substituted or unsubstituted C6- to C10-aryl, and the radicals R8a and R9a, R8b and R9b, R8c and R9c, R8d and R9d, independently of one another, can in each case together also form a cyclic hydrocarbon radical having 2 to 8 carbon atoms which can have one or more identical or different hetero atoms selected from the group consisting of O, S and NR11a and R11a can have the meanings given for R11,
• with an aluminum compound of the formula (II) or formula (III) or a mixture of compounds of the formulas (II) and (III),
• (R14)3-pAlHp (II),
• wherein
• Al is aluminum and
• R14 is a branched or unbranched alkyl radical having 1 to 5 carbon atoms and
• p is 0 or an integer from 1 to 3,
• MAlH4 (III),
• wherein
• Al is aluminum and
• M is lithium, sodium or potassium.