TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises reacting a 2-phenyl-pyrimidine compound of formula (III) with a 2-phenyl-pyrimidine compound of formula (IV), in the presence of a base and a catalyst in a solvent. Preparation of (II) comprises reacting a 4-phenyl-pyrimidine compound of formula (V) with a 4-phenyl-pyrimidine compound of formula (VI) in the presence of a base and a catalyst in a solvent.X1 = halo such as bromo or iodo;X2 = -B(OH)2, -B(OY1)2 or boronic acid group of formula (a) or (b);Y1 = 1-18C alkyl;Y1 = 2-10C alkylene group, such as -CY3Y4-CY5Y6- or -CY7Y8-CY9Y10-CY11Y12-;Y3-Y12 = H or 1-18C alkyl, preferably -C(CH3)2C(CH3)2-, -C(CH3)2CH2C(CH3)2- or -CH2C(CH3)2CH2-; andY13, Y14 = H or 1-18C alkyl. Preferred Definitions:    Ar1, Ar2, Ar1a, Ar2a = phenyl, pyridin-3-yl, pyridin-4-yl, pyridin-2-yl, biphenyl or 3-(3-pyridyl)phenyl.    SPECIFIC COMPOUNDS - 16 Compounds (A) are specifically claimed e.g. 4-(3-(3-(2,6-diphenylpyrimidin-4-yl)phenyl)phenyl)-2,6-diphenyl-pyrimidine of formula (Ia), 4-(3-(3-(2,6-bis(3-pyridyl)pyrimidin-4-yl)phenyl)phenyl)-2,6-bis(3-pyridyl)pyrimidine, 4-(3-(3-(2,6-bis(4-pyridyl)pyrimidin-4-yl)phenyl)phenyl)-2,6-bis(4-pyridyl)pyrimidine, 2-(3-(3-(4,6-diphenylpyrimidin-2-yl)phenyl)phenyl)-4,6-diphenyl-pyrimidine and 2-(3-(3-(4,6-bis(3-pyridyl)pyrimidin-2-yl)phenyl)phenyl)-4,6-bis(3-pyridyl)pyrimidine.    EXAMPLE - 2,4-Diphenyl-6-(3-(4,4,5,5-tetramethyl-(1,3,2)dioxaborolan-2-yl)-phenyl)-pyrimidine (5.55 g), 4-(3-bromophenyl)-2,6-diphenyl-pyrimidine (4.50 g) and potassium phosphate tribasic monohydrate (14.1 g) were degassed with argon. Dioxane (40 ml), toluene (100 ml) and water (25 ml) were added. The mixture was degassed with argon. 2-Dicyclohexylphosphino-2',6'-dimethoxybiphenyl (286 mg) and palladium(II) acetate (261 mg) were added. The reaction mixture was stirred for 24 hours at 100 degrees C. 1% Sodium cyanide solution (40 ml) was added and the reaction mixture was refluxed for 1 hour and worked up to give 4-(3-(3-(2,6-diphenylpyrimidin-4-yl)phenyl)phenyl)-2,6-diphenyl-pyrimidine.