Iodine → 2-{4-[6-(Tert-butyl-dimethylsilanyloxy)hexyl]-phenyl}-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane

HRID 2242778Notes

Reaction equation

HRID 2242778 reaction equation
II.Br[CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][O:10][Si:11]([C:14]([CH3:17])([CH3:16])[CH3:15])([CH3:13])[CH3:12].I[C:19]1[CH:24]=[CH:23][C:22]([B:25]2[O:29][C:28]([CH3:31])([CH3:30])[C:27]([CH3:33])([CH3:32])[O:26]2)=[CH:21][CH:20]=1.[NH4+].[Cl-]>CC(N(C)C)=O.[Zn].C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2].II.C1COCC1>[Si:11]([O:10][CH2:9][CH2:8][CH2:7][CH2:6][CH2:5][CH2:4][C:19]1[CH:24]=[CH:23][C:22]([B:25]2[O:29][C:28]([CH3:31])([CH3:30])[C:27]([CH3:33])([CH3:32])[O:26]2)=[CH:21][CH:20]=1)([C:14]([CH3:17])([CH3:16])[CH3:15])([CH3:13])[CH3:12]

Participants

10

Reactant 4

HCID 807IodineHCID 25517Ammonium ChlorideHCID 4260352(6-Bromohexyloxy)-tert-butyldimethylsilaneHCID 114616544-Iodophenylboronic acid pinacol ester

Product 1

HCID 592073242-{4-[6-(Tert-butyl-dimethylsilanyloxy)hexyl]-phenyl}-4,4,5,5-tetramethyl-[1,3,2]dioxaborolaneYield 73%

Reagents, catalysts & solvents 5

HCID 807IodineCatalystHCID 23994ZincCatalyst2×HCID 178418228Bis(cyclopenta-1,4-dien-1-yl(diphenyl)phosphane);dichloropalladium;iron(2+)CatalystHCID 8028TetrahydrofuranSolventHCID 31374DimethylacetamideSolvent

Conditions

Temperature
85 °C

Procedure

To a suspension of zinc powder (5.0 g, 76.46 mmol) in anhydrous DMA (30 ml) is added iodine (0.5 g, 2 mmol). This mixture is stirred until the red color of I2 disappeared (ca. 2 min), followed by the addition of (6-bromohexyloxy)-tert-butyl-dimethylsilane (15.0 g, 50.79 mmol) and the mixture is stirred at 85° C. for 4.5 h, then cooled to room temperature and excess zinc allowed to settle. In another flask charged with anhydrous THF (30 ml) is added 2-(4-iodophenyl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (15.0 g, 45.46 mmol) and Pd(dppf)Cl2 (0.85 g, 0.10 mmol). This mixture is stirred for 10 min, then the solution of organozinc reagent is transferred by cannula into the flask. The reaction mixture is stirred overnight (˜16 h) at room temperature. Sat. aq. NH4Cl solution is added and the mixture is extracted with ethyl acetate (3×70 ml). The extracts are dried (Na2SO4) and evaporated under reduced pressure. The residue is purified by column chromatography, eluting with petrol/ethyl acetate (10:0 to 4:1), to give a brown oil (13.83 g, 73%). 1H NMR (300 MHz, CDCl3): δ(ppm) 7.70 (d, J=7.9 Hz, 2H, Ar—H), 7.14 (d, J=7.9 Hz, 2H, Ar—H), 3.54 (t, J=6.6 Hz, 2H, OCH2), 2.56 (t, J=7.3 Hz, 2H, ArCH2), 1.27-1.65 (m, 20H, CH2 and CH3), 0.85 (s, 9H, CH3), 0.05 (s, 6H, CH3); 13C NMR (75 MHz, CDCl3): δ(ppm) 146.3 (quat.), 134.9 (CH), 127.9 (CH), 83.6 (2×quat.), 63.3 (CH2), 36.2 (CH2), 32.9 (CH2), 31.4 (CH2), 29.1 (CH2), 26.1 (3×CH3), 25.8 (CH2), 24.9 (4×CH3), 18.4 (quat.), −5.2 (2×CH3).

Workup

  1. custom(ca. 2 min)
  2. temperaturecooled to room temperature
  3. stirringThis mixture is stirred for 10 min
  4. stirringThe reaction mixture is stirred overnight (˜16 h) at room temperature
  5. extractionthe mixture is extracted with ethyl acetate (3×70 ml)
  6. dry with materialThe extracts are dried (Na2SO4)
  7. customevaporated under reduced pressure
  8. customThe residue is purified by column chromatography
  9. washeluting with petrol/ethyl acetate (10:0 to 4:1)

Sources & evidence

ORD record
ord-a76654b8de544926ac26baa192a4d40b
Source dataset
uspto-grants-2010_03
Patent number
US07674397B2

Reaction notes

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