Piperidine derivative, liquid crystal composition and liquid crystal display device

1. A compound represented by formula (1):

wherein, in formula (1),

R 1 , R 2 , R 3 and R 4 are independently hydrogen or alkyl having 1 to 4 carbons, and R 5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons;

ring A 1 is 1,4-cyclohexylene, 1,4-cyclohexenylene, 3,4-dihydro-2H-pyrane-2,5-diyl, 3,4-dihydro-2H-pyrane-3,6-diyl, 3,6-dihydro-2H-pyrane-2,5-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, decahydronaphthalene-2,6-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl or naphthalene-2,7-diyl, and in the rings, at least one hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 5 carbons, alkoxy having 1 to 5 carbons, or alkyl having 1 to 5 carbons in which at least one hydrogen is replaced by fluorine or chlorine, and one hydrogen may be replaced by a monovalent group represented by formula (P-1);

wherein, in formula (P-1),

R 1 , R 2 , R 3 and R 4 are independently hydrogen or alkyl having 1 to 4 carbons, and R 5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons;

Z 2 is a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one —CH 2 — may be replaced by —O—, —S—, —CO—, —COO— or —OCO—, and at least one —CH 2 —CH 2 — may be replaced by —CH═CH— or —C≡C—, and in the groups, at least one hydrogen may be replaced by fluorine or chlorine; and

in formula (1),

Z 1 and Z 2 are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one —CH 2 — may be replaced by —O—, —S—, —CO—, —COO— or —OCO—, and at least one —CH 2 —CH 2 — may be replaced by —CH═CH— or —C≡C—, and in the groups, at least one hydrogen may be replaced by fluorine or chlorine; and

a is 0, 1, 2 or 3.

2. The compound according to claim 1 , wherein, in formula (1),

R 1 , R 2 , R 3 and R 4 are independently hydrogen or alkyl having 1 to 4 carbons, and R 5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons;

ring A 1 is 1,4-cyclohexylene, 1,4-cyclohexenylene, 3,4-dihydro-2H-pyrane-2,5-diyl, 3,4-dihydro-2H-pyrane-3,6-diyl, 3,6-dihydro-2H-pyrane-2,5-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, decahydronaphthalene-2,6-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl or naphthalene-2,7-diyl, and in the rings, at least one hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 5 carbons, alkoxy having 1 to 5 carbons, or alkyl having 1 to 5 carbons in which at least one hydrogen is replaced by fluorine or chlorine;

Z 1 and Z 2 are independently a single bond or alkylene 1 to 10 carbons, and in the alkylene, at least one —CH 2 — may be replaced by —O—, —S—, —CO—, —COO— or —OCO—, and at least one —CH 2 —CH 2 — may be replaced by —CH═CH— or —C≡C—, and in the groups, at least one hydrogen may be replaced by fluorine or chlorine; and

a is 0, 1, 2 or 3.

3. The compound according to claim 1 , wherein, in formula (1),

R 1 , R 2 , R 3 and R 4 are independently hydrogen or alkyl having 1 to 4 carbons, and R 5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons;

ring A 1 is 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and in the rings, at least one hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 5 carbons, alkoxy having 1 to 5 carbons, or alkyl having 1 to 5 carbons in which at least one hydrogen is replaced by fluorine or chlorine;

Z 1 and Z 2 are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one —CH 2 — may be replaced by —O—, —S—, —CO—, —COO— or —OCO—, and at least one —CH 2 —CH 2 — may be replaced by —CH═CH— or —C≡C—, and in the groups, at least one hydrogen may be replaced by fluorine or chlorine; and

a is 1, 2 or 3.

4. The compound according to claim 1 , wherein, in formula (1),

R 1 , R 2 , R 3 and R 4 are independently hydrogen or alkyl having 1 to 4 carbons, and R 5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons;

ring A 1 is 1,4-cyclohexylene, 1,4-cyclohexenylene 1,2-phenylene, 1,3-phenylene or 1,4-phenylene, and the rings, at least one hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 5 carbons, alkoxy having 1 to 5 carbons, or alkyl having 1 to 5 carbons in which at least one hydrogen is replaced by fluorine or chlorine;

Z 1 and Z 2 are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one —CH 2 — may be replaced by —O—, —CO—, —COO— or —OCO—, and at least one —CH 2 —CH 2 — may be replaced by —CH═CH—, and in the groups, at least one hydrogen may be replaced by fluorine or chlorine; and

a is 1, 2 or 3.

5. The compound according to claim 1 , represented by formula (1a), formula (1b) or formula (1c):

wherein, in formula (1a), formula (1b) or formula (1c),

R 1 , R 2 , R 3 and R 4 are independently hydrogen or alkyl having 1 to 4 carbons, and R 5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons;

ring A 2 , ring A 3 , ring A 4 , ring A 5 , ring A 6 and ring A 7 are independently 1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-phenylene, and in the rings, at least one hydrogen may be replaced by fluorine or chlorine;

Z 3 , Z 4 , Z 5 , Z 6 and Z 7 are independently a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one —CH 2 — may be replaced by —O—, —CO—, —COO— or —OCO—, and at least one —CH 2 —CH 2 — may be replaced by —CH═CH—, and in the groups, at least one hydrogen may be replaced by fluorine or chlorine; and

b, c, d, e, f and g are 0 or 1, a sum of c and d is 0 or 1, and a sum of e, f and g is 0 or 1.

6. The compound according to claim 1 , represented by formula (1d), formula (1e) or formula (1f):

wherein, in formula (1d), formula (1e) or formula (1f),

R 1 , R 2 , R 3 and R 4 are independently hydrogen or alkyl having 1 to 4 carbons, and R 5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons;

ring A 2 , ring A 3 , ring A 4 , ring A 5 , ring A 6 and ring A 7 are independently 1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-phenylene, and in the rings, at least one hydrogen may be replaced by fluorine; and

Z 3 , Z 4 , Z 5 , Z 6 and Z 7 are independently a single bond, —COO—, —OCO—, —CH 2 O—, —OCH 2 —, —CF 2 O—, —OCF 2 —, —CH 2 CH 2 — or —CH═CH—.

7. The compound according to claim 6 , wherein, in formula (1d), formula (1e) or formula (1f),

R 1 , R 2 , R 3 and R 4 are independently hydrogen or alkyl having 1 to 4 carbons, and R 5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons;

ring A 2 , ring A 3 , ring A 4 , ring A 5 , ring A 6 and ring A 7 are independently 1,4-phenylene or 1,4-phenylene in which at least one hydrogen is replaced by fluorine; and

Z 3 , Z 5 , Z 6 and Z 7 are independently a single bond, —COO—, —OCO—, —CH 2 O—, —OCH 2 — or —CH 2 CH 2 —, and Z 4 is —COO—.

8. The compound according to claim 1 , represented by formula (1g) or formula (1h):

wherein, in formula (1g) or formula (1h), R 6 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons; and h, i and j are independently 0, 1 or 2.

9. The compound according to claim 1 , represented by formula (1i) or formula (1j):

wherein, in formula (1i) or formula (1j), R 6 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons; and k, l and m are independently 0, 1 or 2.

10. The compound according to claim 1 , represented by formula (1k):

wherein, in formula (1k), n is 0, 1 or 2.

11. The compound according to claim 1 , represented by formula (1l):

wherein, in formula (1l), o is 0, 1 or 2.

12. A liquid crystal composition, containing at least one compound according to claim 1 .

13. The liquid crystal composition according to claim 12 , further containing at least one compound selected from the group of compounds represented by formula (2) to formula (4):

wherein, in formula (2) to formula (4),

R 11 and R 12 are independently alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl or the alkenyl, at least one —CH 2 — may be replaced by —O—, and at least one hydrogen may be replaced by fluorine;

ring B 1 , ring B 2 , ring B 3 and ring B 4 are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene or pyrimidine-2,5-diyl; and

Z 11 , Z 12 and Z 13 are independently a single bond, —CH 2 CH 2 —, —CH═CH—, —C≡C— or —COO—.

14. The liquid crystal composition according to claim 12 , further containing at least one compound selected from the group of compounds represented by formula (5) to formula (7):

wherein, in formula (5) to formula (7),

R 13 is alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and the alkenyl, at least one —CH 2 — may be replaced by —O—, and at least one hydrogen may be replaced by fluorine;

X 11 is fluorine, chlorine, —OCF 3 , —OCHF 2 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 2 CHF 2 or —OCF 2 CHFCF 3 ;

ring C 1 , ring C 2 and ring C 3 are independently 1,4-cyclohexylene, 1,4-phenylene in which at least one hydrogen may be replaced by fluorine, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl or pyrimidine-2,5-diyl;

Z 14 , Z 15 and Z 16 are independently a single bond, —CH 2 CH 2 —, —CH═CH—, —C≡C—, —COO—, —CF 2 O—, —OCF 2 —, —CH 2 O— or —(CH 2 ) 4 —; and

L 11 and L 12 are independently hydrogen or fluorine.

15. The liquid crystal composition according to claim 12 , further containing at least one compound selected from the group of compounds represented by formula (8):

wherein, in formula (8),

R 14 is alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and the alkenyl, at least one —CH 2 — may be replaced by —O—, and at least one hydrogen may be replaced by fluorine; X 12 is —C≡N or —C≡C—C═N;

ring D 1 is 1,4-cyclohexylene, 1,4-phenylene in which at least one hydrogen may be replaced by fluorine, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl or pyrimidine-2,5-diyl;

Z 17 is a single bond, —CH 2 CH 2 —, —C≡C—, —COO—, —CF 2 O—, —OCF 2 — or —CH 2 O—;

L 13 and L 14 are independently hydrogen or fluorine; and

i is 1, 2, 3 or 4.

16. The liquid crystal composition according to claim 12 , further containing at least one compound selected from the group of compounds represented by formula (9) to formula (15):

wherein, in formula (9) to formula (15),

R 15 and R 16 are independently alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and the alkenyl, at least one —CH 2 — may be replaced by —O—, and at least one hydrogen may be replaced by fluorine;

R 17 is hydrogen, fluorine, alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and the alkenyl, at least one —CH 2 — may be replaced by —O—, and at least one hydrogen may be replaced by fluorine;

ring E 1 , ring E 2 , ring E 3 and ring E 4 are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene in which at least one hydrogen may be replaced by fluorine, tetrahydropyran-2,5-diyl or decahydronaphthalene-2,6-diyl;

ring E 5 and ring E 6 are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, tetrahydropyran-2,5-diyl or decahydronaphthalene-2,6-diyl;

Z 18 , Z 19 , Z 20 and Z 21 are independently a single bond, —CH 2 CH 2 —, —COO—, —CH 2 O—, —OCF 2 — or —OCF 2 CH 2 CH 2 —;

L 15 and L 16 are independently fluorine or chlorine;

S 11 is hydrogen or methyl;

X is —CHF— or —CF 2 —; and

j, k, m, n, p, q, r and s are independently 0 or 1, a sum of k, m, n and p is 1 or 2, a sum of q, r and s is 0, 1, 2 or 3, and t is 1, 2 or 3.

17. A liquid crystal display device, including at least one liquid crystal composition according to claim 12 .