1,3,2-DIOXABOROLANE, 2,2'-(9,9-DIMETHYL-9H-FLUORENE-2,7-DIYL)BIS[4,4,5,5-TETRAMETHYL]

2, 7-dibromo-9, 9-dimethyl-9H-fluorene (130g, 369 mmol), bis(pinacolato)diborane (225g, 886 mmol) and potassium acetate (217g, 2.22 mol) was suspended in 1.4L of dioxane. The solution was degassed and saturated with argon. Then added PdCl2(dppf)CH2Cl2 (15g, 18 mmol). The reaction mixture was heated to boiling for 4 hours under a protective gas atmosphere. The mixture was filtered and washed with dioxane.After the crude product was filtered, the use of THF in a Soxhlet extractor for the remaining residue was extracted, then filtered. Produce 137g (83percent of theory) of a gray solid. Purity> 95percent (NMR performed in CDCl3). Under nitrogen protection, Intermediate 2-1 (3.52 g, 10 mmol), diboronic acid pinacol (7.62 g, 30 mmol), K2CO3 solution (16 mL, 2 mol/L), Pd(PPh3)4 (0.21 g, 0.18 mmol) were added to the reactor. The reaction was carried out at 90 ° C for 48 h, and purified to give Intermediate 2-2 (3.48 g, 78percent).Preparation Example 13] Preparation of Compound M[241] [242] 2.7-dibromo-9, 9-dimethyl-9H-fluorene (25g, 71.0mmol), bis(pinacolato)diboron, (37.87g, 149mmol), 1, 4-dioxane (300mL), 1, 1'-bis(diphenylphosphino)ferrocene-palladium(II)dichloride dichloromethane complex (0.58g, 0.7mmol), and potassium acetate (13.94g, 142mmol) were mixed and stirred under reflux. After 9 hours, the reactant was cooled to room temperature, and an organic layer was extracted by adding saturated sodium chloride aqueous solution and ethylacetate, dried over magnesium sulfate, and then treated with activated charcoal, followed by filtering with celite. A solid prepared by concentrating the filtrate under reduced pressure was re-crystallized in ethylacetate, thereby obtaining Compound M (30.9g, 61percent).[243] Under an argon atmosphere, Intermediate 4-1. (2.0 g, 5.8 mmol), bis (pinacolatodiboron) (4.4 g, 17. mmol), a palladium (II) chloride diphenylphosphinoferrocenium*methylene chloride complex (1:1) (0.14 g, 0.2 mmol), potassium acetate (3.4 g, 35 mmol) and dimethyl sulfoxide (40 mL) were added to a 200-mL three-necked flask, and the whole was stirred at 80°C for 9 hours. Water (100 mL) was added to the reaction liquid in such a manner that a solid would be precipitated. Then, the solid was dried under reduced pressure. The solid was purified by means of silica gel column chromatography, whereby Intermediate 4-2 was obtained (amount 1.2 g, yield 47 percent).9, 9-dimethyl-9H-2, 7-dipinacolborylfluorene: the solution of 9, 9-dimethyl-9H-2, 7-dibromofluorene (17.6g, 50mmol) in anhydrous THF(100mL) was stirred and cooled to 78 °C, to which the n-Butyllithium(2.5M, 44mL)was added over a period of 30 min.T wo hour slater isopropoxyboronicacid pinacol ester (25.5 mL)was add edand the mixture was still stirred at room temperature for two hours. After the addition of NH4Cl (20percent, 20 mL), tesolvents were removed and the residue was extracted by dichloromethane.The solvent was removed ina vacuum and the crude product was pure enough .Yield:90percent. 1H NMR(CDCl3) δ 1.38(s, 24H), 1.52(s, 6H), 7.76(d, 2H), 7.82(q, 2H), 7.89(s, 2H)(Fig. S2).

Molecular Weight:446.2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:2
Exact Mass:446.2799700
Monoisotopic Mass:446.2799700
Topological Polar Surface Area:36.9
Heavy Atom Count:33
Complexity:682
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes