Liquid crystal compound having benzothiophene, liquid crystal composition and liquid crystal display device

A compound, represented by formula (1):

• wherein, in formula (1),
• R1 and R2 are independently hydrogen, halogen or alkyl having 1 to 20 carbons, and in the alkyl, at least one piece of —CH2— may be replaced by —O— or —S—, at least one piece of —(CH2)2— may replace by —CH═CH—, and in the groups, at least one piece of hydrogen may be replaced by halogen;
• ring A1 and ring A2 are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, 2,6,7-trioxabicyclo[2.2.2]octane-1,4-diyl, naphthalene-2,6-diyl, or pyridine-2,5-diyl, and at least one piece of hydrogen on the rings may be replaced by halogen;
• Z1 and Z2 are independently a single bond or alkylene having 1 to 4 carbons, in the alkylene, at least one piece of —CH2— may be replaced by —O— or —COO—, and at least one piece of —(CH2)2— may replace by —CH=CH— or —C≡C—, and in the groups, at least one piece of hydrogen may be replaced by halogen;
• Z3 is —O— or a single bond;
• L1 is F, CF3 or CF2H;
• and
• a and b are independently 0, 1, 2, 3 or 4, and a sum of a and b is 4 or less, and when a or b is 2 or more, two of arbitrary ring A1, two of arbitrary ring A2, two pieces of arbitrary Z1 or two pieces of arbitrary Z2 may be identical or different.